Worms and Germs Blog : Animal Health & Diseases : University of Guelph : Ontario Veterinary College : Zoonotic Diseases : Guelph, Hamilton, Ontario

One of the common questions accompanying the onslaught of calls I've taken today is "How do you diagnose influenza in pets?"

Clinical signs, such as sneezing, coughing, fever and lethargy, are not useful for diagnosis. Influenza can produce highly variable disease, ranging from almost none to very severe - so you can't look at an animal and say it has influenza just based on the clinical signs. We don't know much about H1N1 influenza in different animal species (including pets), but this type of influenza can probably cause a wide range of disease in animals as well (at least in those it can infect).

The presence of someone in the household with influenza should get you thinking about flu in a sick pet, but it is far from diagnostic. Many, many people have influenza, but very few pets do. There are many other diseases that can produce signs similar to influenza in pets. The health of people in the household is an important thing to know, but we can't jump to conclusions based on the household history alone.

Laboratory testing is required for the diagnosis of influenza, and there are a few options:

• PCR testing of nasopharyngeal (throat) or nasal swabs, or fluid collected from the trachea: This molecular test detects influenza virus RNA. This is the fastest test and it is most sensitive when samples are taken early in disease.
• Serology: This involves testing blood for antibodies against influenza. Two samples are taken 10-14 days apart. If the antibody level rises 4-fold or greater, that is indicative of influenza infection. This is considered the most reliable method of diagnosis but takes time.
• Virus isolation from nasopharyngeal or nasal swabs, or tracheal fluid: Samples are inoculated into eggs to try to grow the virus. This can take quite a while and isolation of the virus can be difficult.

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I was asked this the other day, in regards to a post about pets and recurrent strep infections in people: "You listed a few things to remember and one of them was how the pet might be an "innocent bystander infected by a family member."  Is there any indication that a dog  might get sick from licking a person infected with Group A Strep?"

Streptococcal infections in dogs are very rare. When they occur, they are typically caused by Streptococcus canis, a Group G strep. Group B strep infections have also been reported. I'm not aware of any reports of Group A (Streptococcus pyogenes) infections in dogs, despite the fact that exposure is probably very common.

Group A strep is a predominantly, if not exclusively, human pathogen. It can be found in healthy individuals (e.g. in the throats of 10-15% of healthy kids) and is the main cause of strep throat. Group A strep also causes invasive infections such as cellulitis, various soft tissue infections, and in rare circumstances, necrotizing fasciitis (flesh-eating disease). Considering how commonly healthy people carry this bacterium and how common strep throat is, you have to assume that dogs are frequently exposed to this bacterium from household contacts.

Licking a healthy human carrier would certainly create an opportunity for a dog to be exposed. Licking wounds of patients with strep infections would probably be worse. Since exposure is probably common and we don't really identify problems in dogs with this bacterium, the risk of infection in dogs is presumably very low. However, basic measures should always be used to reduce the risk of exposure to infectious agents. Even though we don't recognize Group A strep as a problem in dogs, you don't want your dog to be the first case. Dogs shouldn't be allowed to lick infected wounds for both the health of the dog and the person. Strict avoidance of people with strep throat doesn't make sense, but licking should perhaps be avoided since the sick person could also be at higher risk for a secondary infection from the multitude of bacteria present in the dog's mouth.

Bottom line... the risk of Group A strep infection in dogs is minimal, but basic hygiene practices can make the risks even lower.

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The recent discovery of H1N1 influenza in a pet ferret has led to another round of concern about the potential impact of H1N1 on pets and pets as a source of human infection. Finding H1N1 in a ferret is not particularly surprising, considering ferrets are susceptible to various (including human) influenza viruses. We shouldn't dismiss the potential that certain pets could become infected by this virus or transmit, it but the overall risks are presumed to be very low. There have obviously been many, many cases of H1N1 influenza in pet owners, yet there is just this one report in a pet (although it's certainly possible that other pets have been infected but not diagnosed). Ferrets may be the biggest concern. Pet birds and pot-bellied pigs may also be at higher risk considering this virus can clearly infect pigs and birds. Cats are probably a bigger concern than dogs because of what we know about cats' susceptibility to (and ability to shed) H5N1 (avian) influenza.

The risks are low to pets and pet owners, but there's rarely a no-risk situation with infectious diseases. A few basic measures should be taken to reduce the risks associated with this pandemic virus:

• If you have (or think you may have) influenza, treat you pet like other people in your family. Avoid contact with them, especially their faces, and pay close attention to hygiene (especially handwashing). This should help reduce the risk of exposing your pet to H1N1.
• If you have influenza, or your pet has been exposed to anyone with influenza, and your pet becomes ill (e.g. respiratory disease, fever, lethargy), contact your veterinarian. Avoid close contact with your sick pet (especially the face) and wash your hands after you handle it.
• Relax and enjoy the company of your pet. The risks of influenza are low.

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A lawsuit against various parties, including a dog, has been tossed out by a Michigan judge. Inez Starks sued the city of Warren, several police officers and Liberty, a police dog, after being bitten during some sort of confrontation in 2007. I don't have any details about the bite, but "unprovoked attack" and "police dog" don't tend to go together. Police dogs can and will bite in certain situations, but these are extremely well-trained and well-handled dogs.  Most people that are bitten by a police dog probably have themselves to blame more than anyone else. Inadvertent bites could potentially result from being an innocent party in the middle of a confrontation, I guess, but there is no indication this person was merely an innocent bystander.

Anyway, the suit was tossed out by the judge. As a good example of sanity in the legal system, the judge fined Starks' lawyer for naming the dog in the suit.

Dog bites are a big deal and the cause of many lawsuits. Dog owners need to take their responsibilities seriously to reduce the risk of bites (and consequently being sued). At the same time, people need to take responsibility for themselves to reduce the likelihood of being bitten when confronted by a dog. Usually, that's focused on "be a tree" training in kids, but not upsetting police dogs is probably another good rule of thumb.

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Here's a recent question: "Can a rabies virus get into the body if you pick up a dead animal the roadway and have a cut on your hand? I understand the animal has to carry the rabies virus but sometimes we don't know what killed the animal. It may be infected and didn't use due diligence or perhaps it just wasn't fast enough. After reading stories here I'm less likely to remove a dead animal. Sometimes they are so juicy, the fluids are flung about and you may get some on your clothes or skin and not know it. How likely is contracting rabies from fluids in a cut? The reason I ask is when I was younger I picked up a dead squirrel with my bare hands and then noticed I had cuts on my hands. I went to a doctor who looked at me like I was crazy but I had that uneasy feeling because I knew rabies is almost always fatal. Of course, I didn't get it but when I watch other people remove dead animals from roadways I cringe. I can't even think about eating roadkill or skinning it for the fur but that's just me."

Good question. You've covered most of the important aspects of risk, which are pretty minimal:

• Animal has to be infected
• Live rabies virus needs to be present
• Rabies virus needs to get into a person's body (not just on it)

Let's look at these individually.

Animal needs to be infected

• You never know whether this is a concern when you find a dead animal. Once it's dead, you can't tell if it's acting strange. In general, it's safest to assume that all such animals are infectious until proven otherwise.

Live rabies virus needs to be present

• I haven't come across good information about how long rabies virus can survive in a dead body outdoors.  It probably varies greatly between different situations, particularly depending on the temperature of the body. For very fresh roadkill, there's certainly a possibility that live virus is still present (if the animal had rabies).

Rabies virus needs to get into a person's body (not just on it)

• Rabies cannot be transmitted through intact skin. Rabies infection is transmitted mainly through bites, cuts and scrapes. Saliva or nervous system (e.g. brain) tissue are infectious. Blood, urine and feces are not.
• If you have contact with a dead animal, avoid any direct contact with your skin, and avoid any activities that could result in splashing of fluids. Transmission of rabies from infected fluids is possible if it comes in contact with broken skin or mucous membranes like the eyes or mouth.
• If intact skin has been contaminated with fluid, wash it thoroughly with soap and water, but don't panic - it's really of minimal concern.
• If your clothes have been contaminated with fluid, take them off right away if possible.  If that's not practical (or legal), take them off as soon as you get home. Put them in the laundry immediately and wash your hands.
• If open sores or other broken skin has been contaminated, wash the area thoroughly with copious amounts of soap and water under moderate pressure. Disinfectants can be used to help clean the wound, but there's no consensus about whether that's necessary - these chemicals can be painful to use and hard on tissue, and the flushing action of the water probably does the most to remove the virus from the area. You should go to a physician, who will get in touch with public health personnel to determine if there is any reason for post-exposure treatment.  If the animal's body is available to test, that's useful. If the brain has decayed too much to be tested properly, it's questionable whether live rabies virus would still be present even if the animal had rabies.  Public health personnel will decide whether they think there is any risk.

Bottom line: the risk of contracting rabies from roadkill is very low. Roadkill contact has never, to my knowledge, been identified as a source of infection. Rabies transmission from dead animals has been documented, however, such as a couple cases of rabies from people preparing dead animals for food.

So, if you see a dead animal by the road, leave it alone. If you are going (for some reason) to touch it, first make sure it's really dead. An injured animal might be much more likely to bite. If it's really dead and you are just trying to move it off the road, use a stick, shovel or something else that doesn't involve you having direct contact with the animal. Other than that, I'm not sure why anyone would want to touch roadkill.

Image (top) from www.michiganimaging.com
Image (bottom) from http://users.frii.com/donlight/archive/97arc.htm

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A study in the Journal of the American Veterinary Medical Association (Murray et al 2009) investigated the rabies vaccination history of dogs and cats diagnosed with rabies in 21 US states between 1997 and 2001. 

• 264 rabid dogs and 840 rabid cats were identified.
• 4.9% of rabid dogs and 2.6% of rabid cats had a history of rabies vaccination.
• Of the 13 dogs that had been vaccinated, only 2 were considered currently vaccinated. Similarly, of the 22 previously vaccinated cats, only 3 were currently vaccinated.
• Texas had the most positive dogs while Pennsylvania had the most positive cats.

This study cannot determine how effective vaccination is. You'd need to know the number of animals that were and were not vaccinated, and then the number that did or didn't get rabies to determine efficacy. The fact that a small number of properly vaccinated animals got rabies shows the vaccine is not 100% protective, which is not surprising.

Vaccination is an important part of rabies prevention, but it's not the only part. Vaccination is a last line of defense - avoiding exposure to rabies is the critical first line. To reduce the risk of rabies exposure, keep your pets under your control at all times. Keep bats out of the house and try to ensure that your house and yard are not welcoming to wild animals. Don't let your pets have contact with wildlife and pay close attention when strangely-acting wildlife are around. Active measures to reduce wildlife rabies such as rabies baiting are also important.

Don't assume because your pet is vaccinated that you don't have to worry about trying to reduce the risk of exposure to rabies.

Don't assume that an animal with neurological disease doesn't have rabies just because it's been vaccinated.

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There is a recent paper in Preventive Veterinary Medicine about a study of Giardia in canine stool samples collected from urban green areas around Pisa, Italy (Papini et al). The authors went to parks and similar areas and collected stool samples off the ground. They then tested the samples for the presence of Giardia and (very importantly) tested the Giardia to determine whether they were types that typically only infect dogs or whether they were types also found in people.

They found that 31% of stool samples contained Giardia. That's higher than in some recent North American reports. The number of Giardia cysts ranged from 2 to 1428 per gram of feces. Less than 1% of the Giardia were types that are of concern for transmission to people. Therefore, they concluded that parks pose a risk to dogs, since there is a good likelihood that dogs could be exposed to Giardia. However, the risk to people from Giardia found in these parks is minimal given the types that were found.

The risks to dogs and people can be decreased by the simple act of picking up poop.

More information about Giardia can be found on the Worms & Germs Resources page, and in our archives.

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A rabies epidemic continues in Bali, with little apparent control and inadequate access to vaccination. Another person died of rabies last week. He was bitten by a dog in July and taken to a local health centre, but rabies vaccine was not administered. It's not clear whether healthcare providers recommended post-exposure vaccination and the person declined or whether they did not offer vaccination. 

Access to post-exposure treatment in such regions is a serous concern. Apparently, up to 50 people a day are denied potentially life-saving post-exposure treatment because of a lack of adequate vaccine supplies. Because of the limited availability, doctors are focusing on treatment of people bitten by dogs in areas that are heavily infected with rabies. That makes complete sense, but it's still not a good situation.  It's not only those heavily infected areas that are a concern. More rabies vaccine needs to be secured so that everyone who has been potentially exposed can be properly treated. Local officials are blaming the current shortage on a holiday weekend, but it's unclear whether the situation is truly going to improve in the near future.

People traveling to any part of Bali need to be aware of the risks. You don't need to cancel your vacation, just use common sense. Don't approach any dogs or other mammalian pets or wildlife. If you are bitten, immediately go a physician. If rabies vaccination is not offered, ask for it. If it's not given, get on the next plane out of the country and get treated. You don't need to be vaccinated immediately after exposure, so don't panic, but you don't want to unnecessarily increase the risks if you have been bitten.

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People sometimes panic after they hear that their pet has been diagnosed with an MRSA infection. ("Dr. Google" doesn’t help because if you search "MRSA" you can come up with a lot of scary information). However, it’s very important to understand that just because MRSA is involved, it does not mean that an animal (or person) has an untreatable infection. In fact, there are typically at least a couple of different treatment options available. That’s not to say that MRSA infections are of no concern, because they certainly are, but you have to maintain some balance.

Two studies presented at the ASM-ESCMID conference on methicillin-resistant staphylococci in animals re-inforce this. Dr. Andy Hillier from The Ohio State University presented a small study looking at 11 dogs with MRSA infections, including skin infections, surgical site infections, soft tissue infections and an ear infection. One dog was euthanized before treatment was started. All of the other 10 dogs survived. Aggressive treatment was needed in some cases, including some that required surgery to remove surgical implants or severely infected tissue. Still, they survived.

Similar results were presented by Dr. Meredith Faires from the University of Guelph. As part of one study, she reported survival of 42/45 (93%) of dogs with MRSA infections. A large percentage of dogs in that study had MRSA skin infections, which would not typically be expected to cause death, so it’s important to consider what types of infections are involved. Studies of invasive infections (e.g. infections of deeper tissues, infections of the bloodstream) presumably carry a much worse prognosis.

Regardless, these two studies provide more evidence that while MRSA can be bad, it’s not automatically a death sentence. With prompt diagnosis and proper treatment, a large percentage of infected dogs (and presumably cats as well) will survive. Prompt diagnosis and proper treatment are the key.

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A Yonkers, New York school has barred a service dog from a school. On the surface, that sounds like a problem and an invitation for a lawsuit (particularly in the US considering the Americans with Disabilities Act (ADA)), but when you hear the details is seems like an entirely logical response.

The "service dog" is a four-month-old puppy that the child, an 8-year-old boy with juvenile diabetes, uses to monitor his blood glucose levels. The boy's family has battled the school board for a year and the the state Division of Human Rights has declared this year that the Spataros had grounds to sue the district over the issue. Of to court they go...

Service animals need to have full access to do their jobs. The question comes down to is it really a proper service animal?  That's pretty subjective and the weakness of the ADA complicates things. In this case, it certainly seems that this is not truly a proper service dog.

• This dog is four months old. That's too young to be a highly trained service animal. It's also too young to properly assess its temperament, and temperament testing is very important for animals with such open access.
• School board officials claim the dog has not been properly trained and is "not a service dog under the existing service animals standards and guidelines."  A minimum of 120 hours of training over 6 months or more is recommended by the International Association of Assistance Dog Partners, something that obviously has not happened with this dog. The person that trained the dog says that the IAADP's guidelines are just suggestions rather than rules that have to be followed. That's true, but they are suggestions by a recognized and informed group, and I'd put their opinions well above someone who thinks a four-month-old puppy can be a proper service animal.
• The school board has also offered to provide a person to assist the child in the classroom, so that the child can attend school without any barriers.

This isn't going to end well. It's going to cost the family and the school board (i.e. the general public) lots of money in lawyer fees. It's going to draw unnecessary attention to this boy and his disease at school.

If someone needs a service animal, they need to get a real service animal. Otherwise, it's just a pet coming along for the ride. There needs to be better regulation of service animals. In the US, the ADA needs to be reviewed so that patients' rights are protected but also so that the public is protected from inappropriate animals. Bad service animals hurt the credibility of real service animals and the people they serve.

Image from http://www.lohud.com.

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Norfolk, VIrginia's MyCityTalk.com has an article entitled "The Truth About Pet Vaccinations". It's basically the same as hundreds or thousands of other articles available on the internet purporting to try to set the unwary pet-owning public straight about pet vaccines. Here are some of the highlights.

The evidence against vaccinating, however, is overwhelming.

• What evidence? Someone's commentary? Sure, there are hundreds of those. Real scientific proof? Nope. No one is going to dispute that vaccine reactions and other problems can occur. That's clear. At the same time, vaccines clearly save lives and reduce illness. There is certainly a cost-benefit to consider, but non-evidence-based statements like this don't help. The risks and benefits do need to be considered when designing a vaccination program. Real evidence should be used, however.

It is more and more common to see cancer in dogs and cats under 5 years of age.  Autoimmune diseases are on the rise as well.

• Maybe, although you have to be careful interpreting that. We have much better diagnostic tests now and can detect diseases we couldn't diagnose before. Also, animals that are alive because they didn't die of an infectious disease are able to develop these conditions.  You cannot simply attribute such a trend to modern vaccine practices without looking at the other factors that may be involved.

Vaccinations do help prevent serious illnesses, but they should be used with restraint.  Before vaccinating, consider the risk.

• Absolutely. Best piece of advice in the article.

If your cat is indoor only and will never be exposed to unvaccinated animals, the risk of infection is low.

• While the risk of exposure is LOWER for indoor cats, it's not zero. It's amazing how many "indoor" cats come into vet clinics after being hit by a car or getting into a fight with a wild animal. Indoor cats can escape. Also, other animals can get inside, particularly bats - a source of rabies exposure.

Request individual vaccines and vaccinate at least three weeks apart if possible.

• There's little to no evidence that using combination vaccines is a bad thing for your average pet. Also, individual vaccines aren't available for all diseases. Further, if you only vaccinate for one disease at a time and space them three weeks apart, it's going to take a longer time to have an animal with protective immunity. It makes it a lot more expensive too.

If your cats go outside and you have rabies in your area, give a rabies vaccine at six months of age.

• This sentence should start at "give."  Every animal in an area where rabies may be present must be vaccinated, regardless of whether it goes outside.

Vaccinations do not need “boosting”

• Says who? This is a generalization that can cause problems. For some vaccines in some animals, a single dose may be adequate, but it's certainly not true for all. Some vaccines work better than others. Some diseases are more amenable to good vaccination prevention. Some vaccines are probably good for a long time, if not life-long. But not all of them.

Simple blood tests can determine if your companion’s antibody levels for parvovirus and distemper remain high enough to resist infection.

• Nope. You can determine antibody levels but no one really knows how to interpret them (i.e. what level means the animal will be protected). Antibodies are only one component of vaccine protection.

The currently licensed leptospira bacterins do not contain the serovars causing the majority of clinical leptospirosis today, so it is generally not a useful vaccine. 

• That's true for certain areas. In some regions, the vaccines strains are protective for the strains causing disease.

Homeopathic Nosodes are an alternative some guardians are using when choosing not to vaccinate. 

• There is no evidence whatsoever that nosodes do anything but make money for people who sell them.

They (nosodes) do not produce titers against these diseases like a vaccination.

• That's because they don't do anything.
  

Never vaccinate a sick or weakened animal.

• Good advice.

Educate yourself.  Your veterinarian cannot make this decision for you, nor should they.  You are your companion’s guardian.  It is your responsibility to give them the best care you can by researching and carefully weighing your decisions about their healthcare.

• That's true. However, you need to make sure you get good advice from all sources. You should consult with your vet and feel free to ask any questions. You should also scrutinize information available on the internet. Vaccination recommendations have changed in recent years, with longer intervals between boosters, and they certainly may change further as we learn more. I'm perfectly happy stretching out vaccine intervals based on good data. My pets don't get vaccinated every year. The key is to base decisions and changes on evidence so that we maintain the effectiveness of this critical disease-prevention tool.

The original source of the article was actually the Healthy Pet Journal, an online "journal" (site) published by a holistic/naturopathic veterinarian (who of course runs a clinic specializing in such services).  Always consider the source of what you're reading and the potential biases that come along with it.

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A friend recently asked me about having service dogs in classrooms. Her sister, who is a learning resources teacher, told her about an autistic child who will be attending her school with a dog. The dog prevents the child from bolting and helps reduce anxiety. She thought this was an interesting topic because of the various pros and cons that need to be considered, and I certainly agree. It may seem simple at first glance, but when you think about it, it's a rather complex situation.

Contact with animals always comes with some risk. We can never eliminate the risk entirely. What we need to do is determine how to maximize the benefits and minimize the concerns, and ultimately decide whether the benefits are worth the risks.

In this situation:

Potential concerns/risks (to the child and/or those around him/her):

• Zoonotic disease transmission
• Bites/scratches
• Allergies
• Anxiety in children/adults who are fearful of dogs
• Management issues (e.g. who's responsible for making sure the dog gets walked)
• Classroom disruption (e.g. barking, whining, wandering)

Benefits:

• Letting the child attend and get the most out of school
  

That's a pretty big benefit, and it's clear this is a good situation as long as the risks are controllable.

What should be done in a situation like this?

• The true need for the dog has to be assessed. Is it really beneficial? Presumably yes, but the question has to be part of the assessment. There should be a formal evaluation/way to determine that "yes, this animal is needed so we should do everything we can to facilitate it." It doesn't  need to be a restrictive process at all, but it should be in place. (The situation in the US with the ADA complicates this - pretty much anyone can say they have a service animal and the amount of scrutiny that can be applied is minimal. More discussion about this can be found in a previous post, just click here).
• The dog should, ideally, come from a recognized service dog organization. This ensures that the dog/person pair is properly evaluated and the dog is trained. If this is not possible, then the next best thing is for the pair to be involved with a service organization so they get similar (but after-the-fact) training. Getting a formally trained dog may be difficult under some conditions because, while some service dog types (e.g. guide dogs for the blind) are well established, formal programs to provide trained dogs for many other conditions are uncommon or or non-existent.
• The school board should be notified as early as possible. This gives them the chance to make any necessary arrangements.
• Parents of other children in the classroom should be notified. They don't need to be told why the dog is needed (privacy of the student bringing the dog is an important issue), but they should be told a service dog will be in the class and what the school will do to reduce any potential problems. If there are any concerns (e.g. serious allergies, fear of dogs) they should be allowed to move their children to another class without any hassles. Ideally this should be done before the school year starts to reduce any possible stigma of someone being moved because of the dog.
• The teacher should be educated about risks and benefits of therapy dogs. The teacher is a critical link as he/she will oversee routine management of the animal. The teacher needs to understand the benefits of service animals in order to accept the animal in the class. The teacher also needs to understand the potential problems so he/she takes his/her role in management of the situation seriously.
• General hygiene practices (e.g. hand washing after touching the dog) should be emphasized and enforced.
• Any "incidents" must be recorded and reported. Furthermore, follow up to figure out  what happened, why and how it can be prevented is crucial. Any aggressive or other disruptive behaviour by the dog cannot be tolerated and requires an immediate review. A proper service dog should not pose any significant behavioural risks (e.g. biting, barking during class, wandering around). The less the scrutiny of the dog at the start, and the less the specific training, the greater the likelihood of such problems occuring.
• The dog's veterinarian should know it's a service animal. The dog must be examined by a vet at least yearly, and at a minimum it must be properly vaccinated against rabies. If the dog becomes sick, it must be taken to a vet promptly. If the vet identifies a disease that might be transmissible to people, the dog must not go to school until the risk period for transmission has passed.
• A plan must be established for walking the dog and handling feces. The dog should not be taken to defecate on the playground. It should have a separate grassed area in which to defecate that is away from where children play. Feces must be promptly removed and disposed of, and hands washed.

Service animals can be a contentious and emotional topic. They certainly do provide tremendous benefits to some people, so we need to do what we can to facilitate them. At the same time, we need to properly manage the situation to reduce risks to others. Usually, a thorough proactive review of risks and benefits, and a detailed discussion of what will be done, can greatly reduce any concerns and maximize the benefits. They key is actually thinking about these issues and doing something about them before there is a problem.

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In April, I wrote about an ongoing rabies outbreak in the popular tourist destination of Bali. Because of widespread rabies in stray dogs and fatal human infections, there were calls for the government to take aggressive action and for tourists to be aware of the risk. Apparently, things haven't improved much since then.

At least 9 people have died of rabies in Bali in slightly over a year. That's completely unacceptable for a preventable disease.

The latest victim (whose father-in-law died of rabies in August) was from an area that has not been officially declared as being part of the epidemic, so it has not received much government support. She was bitten by a stray dog in August. In any rabies-endemic area (even in the absence of an outbreak), that's clearly an indication for post-exposure treatment. However, she did not receive post-exposure treatment until 15 days after the bite, by which point it was obviously ineffective.

• Rabies post-exposure treatment must be started as soon as possible. If you wait until signs of rabies are present, death is almost certain.
• Be informed and be your own advocate. The family in this case may very well have pushed for post-exposure treatment, but it's critical to look out for yourself. If you have potentially been exposed to rabies, make sure you get treated.
• If you are going to Bali, don't be paranoid about rabies. Be smart. Avoid any contact with dogs (especially strays) and other wildlife. If you are bitten, get medical care immediately. If the animal isn't identified and quarantined for 10 days to make sure it doesn't have signs of rabies, you need post-exposure treatment. If you can't get it in Bali, get out and get to somewhere where you can be properly treated.
• If you are traveling to Bali (or any other rabies-endemic area) with the intention of working with wild or stray animals (especially dogs), get vaccinated before you go.
• More aggressive rabies control and education (including physician education) efforts are needed in Bali. Clearly, this outbreak is not under control and the fact that the latest death occurred in a new region suggests that this problem could be spreading.

More information about rabies can be found on the Worms & Germs Resources page.

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When it comes to methicillin-resistant staphylococci in pets, MRSA (methicillin-resistant S. aureus) gets most of the attention. That's fair since it's emerging as an important health problem, and can be transmitted between pets and people. Now another staph, MRSP (methicillin-resistant S. pseudintermedius) is getting more attention, and it's actually a more common cause of infections in dogs and cats compared to MRSA. There are also some other methicillin-resistant staph that get much less attention. One is methicillin-resistant S. scheliferi (MRSS).

There are actually two different subspecies of this bacterium, S. schleiferi subsp. coagulans and S. schleiferi subsp. schleiferi. Staphylococcus schlieferi subsp. coagulans is the coagulase-positive subspecies. (Coagulase testing is one of the main ways staph species are classified.) Sta[hylocccus schleiferi subsp. schleiferi is coagulase-negative. In general, coagulase-negative staph are considered to be minor concerns and rare causes of disease other than in sick, compromised individuals in hospitals. However, it looks like S. schleiferi subsp. schleiferi is an exception to that rule, as it is able to cause disease in otherwise healthy dogs and cats.

Both S. schleiferi subtypes predominantly cause skin and ear infections. As with other staph, methicillin-resistance is a concern and is increasing. Methicillin-resistant S. schleiferi (MRSS) rates appear to be increasing, which is a concern because methicillin-resistant staph infections are harder to treat due to their resistance to many antibiotics.

One factor that limits our knowledge of the role of MRSS (and really, S. schleiferi in general) in disease is the fact that many, if not most, diagnostic laboratories don't try to differentiate it from S. pseudintermedius because the two species are very similar. (Sometimes, labs don't even try to differentiate any of the coagulase positive staph, including S. aureus).

While MRSA in pets is a public health concern, there is probably much less to fear from MRSS. Staphylococcus schleiferi infections in people are quite rare and there is currently no indication that pets are an important source of human infection. However, given our limited knowledge of this bacterium, it's wise to take some degree of precaution around animals with MRSS infections, particularly basic measures such as avoiding direct and indirect contact with infected sites, and good handwashing habits. These are the same general recommendations for pets with MRSP, and more details about this are available on the Worms & Germs Resources page. 

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Rabies baiting is a common and effective way of controlling rabies in some wildlife populations, particularly skunks, raccoons and foxes. It involves dropping edible rabies vaccine, by airplane or by hand, into targeted areas. Millions of rabies baits are used across North America and baiting programs have been cited as a key aspect of wildlife rabies control. In one year, 1.3 million baits were dropped in targeted areas of Southern Ontario alone over a two-month period. A good series of pictures of rabies baiting is available here.

Rabies baits are usually a small rectangular block comprised of something that smells or tastes attractive to the targeted wildlife into which a liquid vaccine has been added. Some use fish meal and fish oil to attract wildlife. Others use combinations of fats, icing sugar, vegetable oil and artificial marshmallow flavour (don't ask me why - I'm certain there's a reason but I don't know if they've done taste-testing).

Often, the local public is notified in advance of the drops being made, and it is recommended that kids be closely supervised outdoors for a week or so to ensure they don't come into contact with the baits. It is also often recommended to keep pets indoors or on leash during the same period. (Pets are much more likely to be exposed to and to eat the vaccine than kids). It's also recommended that you wash your hands thoroughly if you have contact with a bait.

Rabies baits are quite safe, and these recommendations shouldn't cause concern. It's a case of being overly cautious. The baits are safe to touch, but it is still recommended that you don't touch them (if nothing else, they may make your hands smell pretty bad). Ingestion of a rabies bait by a person or pet is also unlikely to cause a problem. Any adverse affects are more likely to occur due to the non-vaccine component of the bait, particularly because of the typically high fat content. Ingestion of a lot of baits could certainly cause vomiting or diarrhea in a dog, just like ingestion of large amounts of other inappropriate foods.

Some groups recommend that you contact Poison Control if your pet has been exposed to a bait, but I'm not sure what they'd do in such a case. Other groups ask you to report to them that a pet ingested the bait, likely so they can consider exposure of people and pets when determining target areas for the next year. There's similar variation in recommendations if a person ingests the vaccine. Often it is recommended that public health be notified so they can record it, but it's very unlikely anything would be done.

On a related note, you cannot use rabies baits as a free way to vaccinate your pet. It might work, but there is no way to know, and if your pet is exposed, it would be considered unvaccinated if it was not properly vaccinated by a veterinarian with an appropriate dog/cat vaccine.

Image from: http://www.mnr.gov.on.ca/en/Business/Rabies/2ColumnSubPage/275904.html

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A recent post that discussed, among other things, expired antibiotics generated a lot of comments. Some accused me of various things and stated their belief that expired drugs are fine and that requiring antibiotics to be prescribed is a global conspiracy. I'll leave the conspiracy theory alone and just address the issue of expired drugs.

Expiry dates must be provided by manufacturers. They are essentially a guarantee that the stated level of active ingredient will be present at least until the expiry date. Drugs don't instantly vanish the day after, but once you have passed the expiry date, you no longer can be certain about what is present. It's possible the full amount is present, but it's also possible that less is present, and it's impossible to predict. If you don't know how much is present, you can't be certain that you are giving the proper dose. Giving inadequate doses is associated with treatment failure and increased likelihood of antibiotic resistance developing. Therefore, unless you have a pharmacology lab in your house (or readily accessible) to test expired drugs, you shouldn't use them.

It's not just my opinion.  Here's what some other groups say on the subject:

Centers for Disease Control and Prevention (CDC): "...make sure you properly dispose of leftover and expired antibiotics."

University of Michigan University Health Service: "Do not take expired antibiotics."

The Alliance for Prudent Use of Antibiotics quotes Dr. Alfred DeMaria, an Assistant Commissioner at the Massachusetts Department of Public Health (MDPH) suggests that "stockpiling of antibiotics is strongly discouraged because it could lead to inappropriate patient decisions to self medicate, incomplete courses of antibiotics that might select for resistant organisms, the eventual use of expired medications, and the depletion of national supplies for medically-indicated uses. Antibiotics should be selected according to the specific infection of concern."

The advice from these respected groups, who have no financial stake in the sale of drugs, sounds pretty clear to me. Trying to save a little money by re-using expired antibiotics is a bad idea. The infection might get better, but it might not. If it doesn't then the animal (or person) will be sick longer and may require more intensive (and expensive) treatment. If antibiotic resistance increases because of the use of inadequate doses, then more expensive drugs may be required and infections may be harder to treat. None of these are worth the potential cost savings.  This is a different situation than using expired drugs like painkillers for your headache. If those drugs are no longer effective, the worst thing that will probably happen is you won't get better, which you would know in short order and be able to address. With antibiotics it's harder to tell whether they are working early on during treatment (the critical time), and treatment failure could have much more serious consequences, both for the pet and for drug resistance.

When antibiotics expire, get rid of them.  Always complete prescriptions as directed and you won't have leftovers to worry about.

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Skin and soft tissue infections increasingly caused by highly drug-resistant bacteria, along with various concerns about antibiotic use, have led to a desire to find non-antibiotic approaches to treatment of these infections. Tea tree oil has some potent antibacterial properties when tested in the lab, and there are some studies indicating it might be effective for the treatment of certain infections. Some work that we've done in my lab shows promising activity of a few different essential oils against MRSP.  Some of these oil may be similarly useful treatments for certain infections. 

However, as I've stated before, we need to make sure that we adequately investigate safety of any new drug or therapy. All natural does not mean safer. If something kills bacteria, we need to make sure that it doesn't also harm an animal's cells and tissues.

Tea tree oil can cause damage to skin and soft tissue cells, but it's unclear whether this is really a problem during short courses of treatment. Nonetheless, in humans it has been recommended that tea tree oil not be used for treatment of burns because of concerns about tissue damage.(Faoagali et al, Burns 1997)

Another concern is toxicity from ingestion. This isn't usually a concern in adults, but there are a couple reports of children that became seriously ill (neurological abnormalities, progressive unresponsiveness... fortunately temporary) after ingestion of small volumes of tea tree oil. This leads me to have concerns about ingestion of the oil by dogs and cats if they lick areas where it has been applied, or eat bandages soaked in oil. They probably wouldn't ingest that much, but it's possible.

At this point, the jury is still out on the usefulness of tea tree oil. There are some potentially beneficial aspects and some safety issues that need to be clarified. In the interim, if you want to use tea tree oil:

• Recognize it's not a proven therapy. Don't use it in place of conventional treatment recommended by your vet.
• Keep it out of the reach of children and pets.
• Be judicious about the amount you use, and make sure pets don't lick it off.
• If the infected site seems to get worse after tea tree oil is used, stop applying it and see your veterinarian.

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Tuttle Animal Medical Center in Florida has reported six dogs with severe bloody diarrhea, vomiting and fever, over the past month. The affected dogs were from the same general area in Sarasota County, and all but one died within 24 hours. However, care must be taken when interpreting information such as this. Apparently, most dogs were owned by people with limited finances, so it's hard to say whether they would have died if aggressive (and expensive) treatment could have been provided. A disease like parvovirus is highly fatal without treatment, but survival rates are excellent if proper treatment is provided.

Initial testing of these dogs to identify the causative agent has been unsuccessful, including a rapid in-clinic test for parvovirus. Because of limited finances, complete diagnostic testing has not been performed, and it's likely that only a very limited range of possible causes have been investigated. That's a problem with a user-pay system such as this. There's no incentive for owners of dead pets to pay for further testing that could help understand the problem and/or help other peoples' pets.

Various experts have been consulted, but it sounds like there is minimal material (e.g. saved fecal samples) to use for further testing.  Trying to make a diagnosis based on clinical signs and basic laboratory data collected by the clinic during standard work-up and treatment is essentially impossible. Veterinary infectious disease expert Dr. Cynda Crawford told VIN News Service by e-mail last Wednesday "There is very little case material to work with, so am struggling with meaningful diagnostic approaches,...Everything is basically speculation at this point."

Florida's Division of Animal Industry is apparently "monitoring the situation." At this point, there's nothing that can really be done, but hopefully assistance with testing will be provided should further cases be identified. One official from this agency speculated that E. coli O157 could be the cause. That seems pretty unlikely. This bacterium can cause disease in dogs but it's quite rare. Six apparently unrelated cases due to such a rare cause seems pretty unlikely, although it shouldn't be dismissed.

A general tenet of medicine is "common things occur commonly." Situations like this are most often unusual presentations of a common disease (e.g. parvovirus) rather than a new disease. More aggressive diagnostic testing for known causes of disease, along with additional testing to try to identify new pathogens is needed if further cases are identified. Sometimes apparent outbreaks like this go away on their own without any intervention or diagnosis. Only time will tell whether this is a small local event or the "tip of the iceberg."

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Animal bites are very common. Millions of people are bitten every year, and the resulting burden in terms of pain, infection and financial costs is astounding. Dog bites get the most press because they often cause significant trauma. Dogs have larger and stronger mouths, and can bite repeatedly and more aggressively in some attacks. Deaths attributed directly to pet bites pretty much exclusively involve dogs.

Cat bites are smaller and have less chance of causing significant injury to tissues, but they may be more severe in the long run. There's a scientific paper called "Cat bite infections: biological warfare amongst cats," which is a testament to the nasty populations of bacteria that live in cats' mouths. It's not just the presence of bacteria that's a problem (afterall, dogs' mouths are full of potentially nasty bacteria as well) - the nature of cat teeth and the resulting bite wounds is a major factor. Cat bites often result in small but deep puncture wounds. This pushes bacteria deep into the tissues, where they're harder to get rid of and which results in a much greater chance of causing an infection. Furthermore, cats tend to bite areas that are high risk for development of bad infections, especially hands, which have a complex and susceptible network of tendons, tendon sheaths, joints and nerves. Bites that appear to be minor can end up causing serious problems, often much worse that an initially more dramatic dog bite.

Really, you don't want to be bitten by either a dog or a cat (or an iguana, hamster, person or anything else). A large percentage of bites are avoidable, and knowing how to interact with animals and read signals of aggression or fear are critical. If you are bitten, prompt and proper care of bites is required to prevent serious, long-term complications.

More information on bites, including management of bites, is available on the Worms & Germs Resources page. The CDC has a podcast that includes information about bite-avoidance that can be accessed by clicking here.

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I'm back from a week away with no internet access, so I have some catching up to do. One of the first things I stumbled across on my return was an article in the Guelph Tribune about a summer kids camp at the Guelph Humane Society. At the camp the kids get exposed to various aspects of animal care and welfare, and have field trips to sites like a Donkey Sanctuary and Butterfly Conservatory. Some parts of it sound quite good, but it's clear that the kids get to have a lot of contact with shelter animals, since playing with the animals is the "highlight of the camp," and as the camp director states "Who wouldn't want to hang out with cats and dogs all day?"

I have nothing against young kids having contact with pets (being the father of three young kids and the owner of multiple pets). Contact with animals is very rewarding for children, and a program to increase awareness about pets, animal care and the problems with overpopulation could be a great thing. However, I'm not sure that this is the best way. I only have a superficial idea of what happens at this camp based on the article, but I have a few different concerns.

Child safety

• Any contact between people and pets carries some (albeit very low) risk of infection. Certain things increase the risk. One is young age. Kids are at increased risk of infection. The day camp had children between 5 and 13 years of age - the young end of this range certainly could be considered a high risk group.
• Another issue is the increased likelihood that animals are shedding infectious agents. Shelter animals are definitely a high risk group, because of factors such as young age, stress, mixing of animals from various sources, illness, and under- (or lack of) vaccination and deworming.
• The lack of good knowledge of temperament of these animals is another concern, as it's harder to predict whether an unfamiliar animal might be more likely to bite or scratch. I assume (hope) that the kids are only allowed to have contact with animals that have been assessed in some way, but it's difficult to know how an animal is going to react in certain situations.
• Another consideration is the sometimes unpredictable nature of contact that kids have with animals. Young kids don't inherently know how to interact with strange animals. Even if they act very well around their own pets, they may act differently in a strange situation with animals that act differently, and not know how to detect or respond to signals that the animal is aggressive or afraid.  Education and supervision are important and should be a part of a program, but you can't instantly eliminate these risks.
• The humane society environment can also be assumed to be pathogen-rich - there is a high likelihood that various surfaces (e.g. floors, counters) throughout the facility are contaminated with various bacteria, fungi and parasites.
• Kids could also transfer infectious agents to the household, something that is of greatest concern if there are very young, elderly or immunocompromised individuals present.

Humane society safety

• Humane societies are at constant risk of infectious diseases, including outbreaks. Outbreaks can cause major problems, including temporary closure, illness in staff or owners of newly adopted animals (e.g. ringworm), or mass euthanasia. Infection control measures can be highly variable in humane societies, and adding a group of kids to the mix certainly doesn't help. The more contact and movement in a facility, the greater the risk of disease transmission. Strict adherence to careful infection control protocols (which is not often the case, even at the best of times) is required. Good practices at the camp such as careful attention to hygiene, restricting contact with certain groups of animals, and very careful supervision could reduce the risk of disease transmission, but you can never eliminate the added risk that this type of program would bring.

Pet safety

• Various infectious diseases could be transported home on the bodies of kids or their clothing. Some of these could pose a risk to any pets in the household. Risks are much greater if there are young, old, sick or inadequately vaccinated pets in the house.

I wonder whether the parents of these children were informed (in writing or otherwise) that their kids would be exposed to a increase risk of infectious diseases, bites and scratches, that they should take measures to reduce the risk of disease transmission when the child returns home, and what precautions are being taken at the camp.

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Brucellosis can be a pretty nasty disease. Most people with brucellosis are infected through ingestion of contaminated food or contact with infected farm animals. Brucella abortus, B. melitensis and B. suis are the most common bacterial species involved. However, there is also another Brucella species, B. canis, which (as the name implies) is associated with dogs. Human infections with B. canis are much less commonly diagnosed than those caused by other Brucella species, but it is possible that this infection actually occurs more often than we realize.

Brucellosis can cause a wide range of problems, but most are rather non-specific such as fever, headache, body aches, sweating and back pain. Recurrent, undulating fever is a common sign and can persist for long periods of time. Disease caused by B. canis is similar to that caused by other Brucella species, but one reason this disease may be underdiagnosed is that screening tests for brucellosis do not cross-react with B. canis. Therefore, a physician might suspect brucellosis, but if the initial test (an antibody test) is negative, the physician is likely to move on to investigate other possibile diagnoses. Specific B. canis blood tests or culture of B. canis from blood or infected sites are required for diagnosis. Overall, it's probably still a very rare disease, but one that certain people should be aware of.

Many dogs that are infected with B. canis have no detectable signs of infection. The bacterium can circulate through the body continually or intermittently, and spread from the gentials (where it likes to reside) for years. Some infected dogs show signs of illness. Reproductive problems, including late-term abortion (miscarriage) and decreased fertility are major problems. Fever, lymph node swelling, diskospondylitis (infection in the spine) and other problems can also develop.

The risk of human exposure is highest in people in close contact with breeding animals, particularly people in contact with dogs that miscarry during pregnancy or kennels with reproductive problems. Most reported human infections involve people in close contact with dogs that miscarry. The risk to owners of household pets (especially neutered pets) is presumably very low.

• People who have been exposed to dogs that miscarry and who subsequently develop signs like fever and aches should make sure their physician considers B. canis infection.
• HIgh risk people (very young, elderly, immunocompromised, or pregnant women) should avoid contact with dogs that have miscarried, or dogs from kennels with reproductive problems or known B. canis infection.
• Care should be taken when handling dogs that have miscarried or are in the process of doing so. Gloves should be worn when handling the dog, aborted fetuses and any potentially contaminated items. Uterine (birth) fluids can have very high levels of B. canis.
• Hands should be washed regularly and after removal of gloves.
• If abortion or reproductive problems are identified in a kennel, testing for B. canis should be performed. If present, an eradication program should be started.

More information on brucellosis in dogs can be found in the Worms & Germs archives.

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In Canada, access to rabies vaccine for animals is restricted to veterinarians (i.e. only vets can buy the product itself and administer it to people's animals). In general, this is an excellent approach because it ensures that the vaccine has been handled and stored appropriately, animals have been vaccinated properly and accurate vaccination records are kept. I certainly wouldn't want rabies vaccine freely available, whereby anyone could buy vaccine, handle it poorly, vaccinate their animal improperly, and yet believe or claim to have a properly vaccinated pet.

The problem with this restriction is the fact that veterinary care is not always available. Specifically, I'm referring remote northern communities that do not have veterinary care on a regular or even a sporadic basis. I received an e-mail the other day from a medical professional in a fly-in First Nations community in Northern Ontario. They have not had a visit from a vet in a while, so the dogs there aren't vaccinated. Unfortunately, a dog was attacked by a wolf recently so it must be considered possibly  exposed to rabies, resulting in euthanasia or long quarantine. The question was about what can be done in those communities to provide rabies vaccine for people's animals. I didn't know, so I inquired with the Canadian Food Inspection Agency, the federal agency in charge of all-things-rabies.

There are actually provisions in Canadian regulations for situations like this (a provision in the Health of Animals Regulations Section 132.4 (2), if you want to know specifically). This allows rabies vaccine to be sold in accordance with written permission granted by the Minister, in specific circumstances such as in a remote area where veterinary services are not readily available. The provincial veterinary association is typically contacted to determine whether or not there is a veterinarian who could arrange to do the vaccinations. If the provincial association agrees that there is no veterinary service available to the community, then permission can be granted to purchase vaccine. 

It's quite a reasonable and logical approach that allows for access to rabies vaccine when needed, but has enough controls in place to ensure that this can't lead to abuse of the exception. People in remote communities in Canada should be aware of this. Some communities get periodic visits from vets but there are many others such as the one in this case that don't have any direct access to veterinary care, and this is a way of at least providing protection for people and pets against rabies.

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A recent question: "If a dog has severe atopy that is poorly managed, and is colonized w/ MRSA  (superficial dermatidis on neck ventrum and axilla) are repeat infections w/ MRSA likely, if the allergies cannot be controlled?"

Dogs with atopy (allergic skin disease) are prone to opportunistic infections because of the abnormal skin "environment" and trauma from licking and scratching. Damage to the skin creates the opportunity for various bacteria to cause infections, including some bacteria that may usually live on normal skin without causing problems.  Most commonly, staphylococci are involved, and this may include skin infections with MRSA (methicillin-resistant Staphylococcus aureus). The likelihood that a dog will develop an MRSA skin infection depends on the likelihood of exposure to MRSA. If the dog is already a carrier (i.e. has MRSA in its nose or intestinal tract), the odds are greater because exposure of the skin to the bacterium is more likely. If the dog is owned by someone with MRSA or someone who visits human hospitals, the risks are likely greater as well because of the increased chance of MRSA exposure via the owner.

For most dogs, the risk of MRSA infection is not high. Fortunately, dogs that are MRSA carriers are typically only carriers for a short period of time. They usually eliminate MRSA carriage naturally within a couple weeks, if re-infection is prevented. So, for a dog that is a carrier or has an MRSA skin infection, if carriage is eliminated and the infection is properly treated, the risk of subsequent MRSA infections should be quite low, as long as there is a not a high likelihood of re-exposure.

Dogs with chronic skin disease should not visit human hospitals in order to reduce the risk of developing MRSA infection. If such a dog is owned by someone who is infected or colonized with MRSA, particular attention should be paid to handwashing to reduce the risk of transmission of MRSA to the dog. In situations other than these, recurrent MRSA infection is probably not a risk if basic hygiene practices are used. If an MRSA infection is present, it must be properly treated - sometimes apparently "repeated" infections are actually infections that were never completely eliminated in the first place.  A key component of management of dogs with atopy (and other chronic skin conditions) is getting the atopy under control so that there is less chance of secondary bacterial infection.

More information about MRSA in pets can be found on the Worms & Germs Resources page.

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Giardia is a relatively common protozoal parasite that can cause diarrhea in people and dogs (among other species). It can also be present in healthy pets, with most studies reporting Giardia shedding in approximately 7% of healthy dogs. While recent research indicates that a large percentage of dogs with Giardia carry types that do not infect people, this parasite is still a concern, particularly in households high-risk households with immunocompromised individuals, very young children and elderly persons.

What do I do if I'm in a high-risk household and my dog is diagnosed with Giardia?

• Genotyping of Giardia from the dog to see if it is a strain that affects humans would be ideal, but this is not readily available outside research labs. Maybe in the future this will become a standard test.
• The dog should be treated according to your veterinarian's instructions. The entire treatment course must be completed.
• All other dogs and cats in the house should be treated at the same time, even if they have been tested and were negative, because we want to avoid "cycling" of Giardia between the pets.
• All animals should be bathed on the first and last day of treatment to reduce the risk of re-infection from Giardia cysts on the fur. This should not be performed by high-risk individuals, and is probably best done at a veterinary clinic or groomer to reduce bathroom contamination, if bathing can't be done outside.
• All animals should be tested after treatment to ensure the infection has been eliminated. This is usually done about 5 days after the last treatment. If antigen testing is used, some animals will still have positive results 5 days after treatment because of dead Giardia still working their way out, in which case re-testing at around day 21 post-tretament is recommended.
• Care should be taken to avoid direct and indirect contact with feces. Close attention to handwashing promptly after cleaning up feces or fecal-contaminated areas is very important. Regular handwashing after contact with pets is always important.

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There are two situations when animals may be quarantined because of rabies concerns:

1. After biting a person.
2. After potentially being exposed to a rabid animal.

The time frame for quarantine in these two situations is quite different because of what the quarantine is meant to accomplish.

Animals that have bitten someone are quarantined for 10 days under observation to see if they develop signs of rabies. Most animals that bite do not have rabies, and this is the easiest way of determining whether the animal could have potentially transmitted rabies by way of the bite. If an animal was rabid and infectious at the time of biting, it would die from the disease within 10 days. Animals can only transmit rabies virus after it has reached the brain and started to spread outwards via nerves - it gets into saliva by working its way down nerves from the brain to the salivary glands. Once an animal gets to that stage of disease, they die quickly. So, if the animal is still alive after 10 days, it was not rabid at the time of the bite. Quarantine is important so that it can be clearly proven one way or the other whether the animal was rabid. If the biting animal was not quarantined and ran away, the recommendation would be to err on the side of caution and treat anyone bitten as if they'd been exposed... but we want to avoid that if at all possible.

The second type of quarantine (for a potentially exposed animal) is based on less solid evidence. The idea in these cases is to keep the potentially exposed animal isolated while waiting to see if it develops signs of rabies, because there is no other reliable test for rabies in a live animal. For example, if an unvaccinated dog gets into a fight with a rabid raccoon, it would be considered potentially exposed. It would be quarantined (or immediately euthanized... the other option) and monitored to see if it develops signs of rabies. The length of quarantine for non-vaccinated dogs is usually 6 months, but this may vary by region. This helps reduce further rabies transmission by ensuring that a dog that develops rabies during the quarantine period is not roaming at large and able to infect people or other animals. One weakness of this approach is the incubation period of rabies, which can be very long. There is not a lot of objective research on which to base the 6 month time frame (unlike the 10 day quarantine described above). After 6 months, it's very unlikely the dog will develop rabies, but we can never say it's 100% because of the rare cases of rabies in humans with extremely long incubation periods. In reality, it's likely that the vast majority of animals that are exposed will develop rabies before 6 months, so it's a reasonable time frame. Would it be better to use 4 or 8 months, or something else? Possibly, we just don't know.

The easiest ways to avoid hassles associated with rabies quarantine are:

• Prevent bites. If your pet is trained and observed properly, it's unlikely to bite anyone, so the 10-day post-bite quarantine shouldn't be an issue.
• Vaccinate your pet. Properly vaccinated pets are not subject to the same long, strict quarantine (although a shorter period of isolation (often at home) is usually still required).

More information about rabies can be found on the Worms & Germs Resources page.

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Recently, I wrote a commentary about the need to better define what service animals are because of potential abuse of regulations regarding service animals and the possibility that illegitimate use of the term could impact true service animals. Here are some good comments from a reader.

As a service dog user and trainer who sometimes lectures at the University of Guelph, I am sorry to see the American-centric slant to this article.  In Canada the guideliines are even more vague and there has to be a charter challenge to support the use of a service dog that has been owner trained.

• The article was intended to discuss the American situation since I was talking about American legislation and responding to problems that people have asked me about in the US. Issues are different in various countries and the legal protections in the US certainly don't apply to Canada.
• The last point raises some concerns. What constitutes "owner trained?" Service animals are highly trained to do their specific task and to work safely in public situations. I'm not convinced owner training makes a service animal. There needs to be at least some degree of supervision/review of the training and certification process.

I use a service dog to mitigate the effects of my invisible disability and the vagueness of the laws related to service dogs in Canada has made travelling and working with my dog difficult.  I get comments that range from "you don't look disabled" (which I usually reply to with -thank you!
neither do you!) to "that dog doesn't look like he is doing anything and how can he help you if he is asleep (believe it or not, he does get to sleep when I stop to work somewhere, but will wake up and work if needed).

• Those are all legitimate concerns and I empathize with the problems you've had. That's why I think the "spirit" of the US's ADA is excellent. Protection needs to be in place for true service animals. Just as important is the need for education about what service animals are, what they do, and where they should be allowed to go. I also think this reader's concerns support my comments: We need to make sure that service animals are properly scrutinized. If people know that service animals are properly trained and regulated, they are less likely to have a problem with them. On the other hand, if people never know whether a service animal is really a service animal, then they may be less likely to give them the degree of respect and access they deserve.

I strongly feel that if you don't need a dog you won't take a dog with you; why would you? It is too much work!  For anyone who would like to take their pet with them to the grocery store, I would be delighted to take them with me to show them what travelling through the meat aisle is like; people stop and stare.  You have to plan your route so that the grocery clerk doesn't park their cart under my dog's nose (no...he won't touch it...but why make his day harder than it needs to be).  You need to be aware of the two year old who is covered in jam who wants to hug the doggy.    And you have to avoid hazards like the display of glass jars that tumbled and broke in front of my dog, surrounding him in glass shards with no way to safely walk out (stand stay! what a useful behaviour).

• Sorry, but I disagree. I think that if a grocery store advertised that it was pet friendly, there would be dogs in there all the time. Some people bring their pets everywhere, no matter how much extra work it is.
• Also, the grocery store example is a great one to highlight concerns. There are public health reasons why we don't want widespread animal access in grocery stores. Check out a previous post about a "service horse" walking through grocery store.
  

Life with a service dog is enriching for certain, but it is not something you want to do unless you need to.  I would advise anyone who is concerned about the illegitimate users to slow down, and think.  We are already protected.  If your dog is causing a problem, you can be asked to leave.

• In Canada you can. In the US you can't. That was the point of the article. In the US, you can't ask someone to make an animal leave except under very specific circumstances that a true service animal should never create. What we need is more protection in Canada and more clarity in the US.

Image source: http://www.assistancedogsofthewest.org

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There's been a lot of talk (hype) in the press about pet bites and MRSA (methicillin-resistant Staphylococcus aureus). This relates to a paper in Lancet Infectious Diseases regarding infections associated with pet bites. Some press articles are more sensational than others, but most are taking the bite infection paper and building in unrelated comments about MRSA in animals to make it seem like there's a major MRSA dog bite epidemic underway.

I realize that MRSA is a hot topic that is easy for reporters to latch onto, but the problem is that the actual research related to MRSA is being taken out of context (and blown out of proportion). MRSA was certainly mentioned in the paper, but it was not the focus of the research nor do the authors play up concerns about pets as a source of MRSA infections. Nevertheless, the impression people are getting from many news articles is that there is rampant MRSA transmission by infected pets.

Is MRSA infection a potential concern after a dog bite?

• Yes, but more because of the bite itself than the particular dog.  MRSA infections that occur after a dog bite are probably the result of contamination of the wound with MRSA from the person's own nose or from another person, for example during a visit to their physician/clinic/hospital. It's possible for MRSA to be in the mouth of the dog and for it to be transferred to the wound during the bite, but that's pretty unlikely. The person bitten or someone treating the wound is a more likely source of the bacterium. So, the bite was the ultimate "cause" of the MRSA infection, because the infection probably wouldn't have developed without that break to the body's normal defensive barriers (i.e. the skin), however the "source" of the infection was (in most cases) NOT the animal.  The same kind of infection could have happened with any similar type of trauma.

What should I do if I'm worried about MRSA and dog bites?

• Worry more about dog bites than MRSA. Bites themselves are major problems, even if MRSA is not involved. The degree of trauma can be significant, and a variety of bacteria can cause serious bite infections, not just MRSA.
• Take measures to reduce the risk of being bitten, both in terms of how you handle and train your dog and how you interact with other dogs.
• If you are bitten, immediately clean the wound as thoroughly as possible. If the bite is over a joint, tendon (e.g. wrist/ankle), prosthesis or genitals, if there is significant trauma or if you have a weakened immune system, you need to see a physician. If you have any other concerns, get examined by a physician promptly.

More information on MRSA in animals can be found on the Worms & Germs Resources page.

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At the same time that the country is drafting an animal welfare law that would ban widespread killing of dogs, a Chinese city has killed 36 000 stray and pet dogs in an effort to eliminate rabies. Since late May 2009, more than 6 000 people in Hanzhong have been bitten or scratched (presumably by dogs), and 12 have died of rabies. Certainly, this indicates multiple problems. One is the massive number of bites and scratches. Contributing factors probably include a large stray animal population, limited routine animal control efforts, and inadequate education of the public regarding bite avoidance. The number of injuries and deaths certainly indicates that an aggressive response is needed. However, there is little evidence that culls (i.e. mass killings of this type) have any effect on controling rabies and animal-associated injuries. Efforts are probably better directed at other forms of population control, vaccination of stray and pet dogs, and education of the public to keep stray dogs away and reduce the risk of bites. These types programs cost money, but the costs of treating 6 000 bites and 12 fatal rabies infections can be enormous. I don't know how many people received post-exposure treatment for rabies, or what such treatment costs in China, but it's estimated to cost  about $1500 per person in North America. That would pay for a lot of rabies vaccine for dogs.

Photo: Hanzhong, China (source: www.panoramio.com)

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A recent study from the Netherlands investigated the prevalence of zoonotic parasites in pet feces and on pets' haircoats. The authors sampled feces and fur from dogs and cats, and looked for Toxocara (roundworms), Toxoplasma, Giardia and Cryptosporidium. All these parasites are of concern from a public health standpoint because they can be found in healthy pets and can also infect people.

Toxocara eggs were found on the haircoats of 12% of dogs and 3.4% of cats. Levels were low, ranging from 1-31 eggs per sample. An important aspect of this study was that they also assessed viability of these eggs, and found that none were viable.  Therefore, even though eggs were present, they were not relevant because they were dead. Exposure to UV light and lack of humiditiy were cited as possible reasons for the death of the eggs.

Toxocara were found in the feces of 4.4% of dogs and 4.6% of cats, which is consistent with other studies of healthy pets.

Toxoplasma was not found in the feces of any cat. (Cats are the hosts for this parasite so dogs weren't tested.)

Giardia was found in the feces of 15% of dogs and 13.6% of cats. However, when these strains were typed, the vast majority were species-specific types that do not cause disease in people. Only 2 of the 15 Giardia samples were assemblage A, a type that is transmissible from pets to people. This is very important to know because crude Giardia numbers don't tell you the whole story. 

Cryptosporidium was found in feces of 8.7% of dogs and 4.6% of cats. However, they were not able to type these parasites to determine if they were species that typically cause infection in humans, or whether they were Cryptosporidium felis or C. canis, which rarely cause disease in people.

The discussion section of the paper contains an interesting and relevant point about exposure to Toxocara eggs on the haircoat of pets. The authors state "Even in the worst case scenario of highly contaminated fur, e.g. with the highest Toxocara [eggs per gram] of 300 and an embryonated rate of 4% from the study of Wolfe and Wright, it is necessary to ingest more than 4 grams of hair, with 12 embryonated eggs per gram, to ingest 50 infective eggs."  Based on these data, exposure to parasites from the haircoat of pets is quite unlikely.  It might be a greater concern with stray or debilitated animals, or with puppies/kittens, who could have much greater coat contamination.

The take home message: Normal contact with healthy pets likely poses minimal risk of transmission of zoonotic parasites. That being said, regularly washing your hands is still a good idea because of the potential for exposure to other types of microorganisms (e.g. bacteria), and in rare circumstances where there may be large parasite burdens on a pet. Good deworming practices, particularly for puppies and kittens, also need to be considered.

Reference: Overgaauw et al, Veterinary Parasitology, 2009.

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Here's a recent question:

"We have a 'new' boxer age 2. The breeder believes in the raw food diet, and not many vaccinations or preventitive treatments. Recently the boxer has been shown to be heartworm positive, and she (the breeder) wants us to take a "holistic" approach to management. Are there any randomized trials to show any benefit to holistic treatment of heartworm?"

The quick answer is NO. There are no “holistic” treatments that have been shown to be effective in randomized trials, nor have any holistic treatments been shown to have any potential effect in in vitro studies. The only proven treatments are “conventional.” I consider it highly unethical to attempt other approaches because: 1) heartworm is a serious disease but one that can often be treated quite successfully and 2) untreated (or inadequately treated) dogs put other dogs at risk because they are sources of infection. Mosquitoes can transmit heartworm from infected dogs to other dogs in the area, and continue the cycle of infection. A serious and transmissible disease is not one for which unproven and likely ineffective treatments should be tried.

Heartworm is a potentially fatal disease that predominantly affects dogs, but can occasionally affect cats as well. It is most commonly caused by the parasite Dirofilaria immitis. It is spread by mosquitoes, which transmit the immature form of the parasite (microfilaria) which are found in the blood of infected animals. Upon being transmitted to a new host by a bite from an infected mosquito, the immature parasites eventually develop into adult worms. These worms lodge in the heart and the nearby blood vessels going to the lungs, and can cause a range of problems (e.g. lethargy, intolerance to exercise). Infection can be fatal - early (and effective) treatment is the key.

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Canadian Guidelines for the Treatment of Parasites in Dogs and Cats have recently been released. These guidelines were developed by an expert panel, consisting of six Canadian veterinary parasitologists and two private practitioners. They provide a good, balanced approach to the treatment of parasites, with an emphasis on the risks present in different regions and in different types of pets. There is very little objective information on which to base some of the recommendations, so many aspects are instead based on expert opinion, not necessarily hard facts, but when data are lacking, that's when opinions from independent experts are most needed. The guidelines provide an overview of recommended treatments along with an explanation of the reasoning.  This document is a useful resource for pet owners and veterinarians alike. There is also discussion about why guidelines in Canada differ from those in the US. To download these guidelines click here.

Note: Development of the guidelines was supported by a pharmaceutical company, but the information they contain was developed by the independent experts mentioned above.

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Recently, I wrote a post about the need for vets and physicians to communicate more, and about concerns that zoonotic diseases get missed because vets deal with animals and physicians deal with people, but few people pay attention to the interface between them. A reader (my father, actually) wrote this comment.

“...is the opposite also true? If I take my sick cat to the local vet, will he advise me to see my physician if I begin to feel ill effects? Are vets trained to know that pets can transfer disease to their owners or in this an emerging part of vet. science?”

It’s a good question and one that doesn’t have a straightforward answer. Vets certainly do get educated regarding zoonoses.  From what I understand from talking to colleagues in the human medical field, there is much more emphasis on zoonoses in the veterinary medical curriculum compared to the human medical curriculum. However, a lot of the focus is on foodborne and waterborne zoonoses, with much less information about companion animal (e.g. dog, cat, horse) zoonoses. Different vets have quite variable knowledge in this area, ranging from excellent to poor. It’s a huge field (I’m still learning more about it all the time), and vets and physicians alike have busy schedules and many other areas where they need to stay current as well, so it’s not unfathomable that zoonoses could get neglected.

So, to answer the question, if you take your sick cat to the vet, it’s unlikely he/she will initially ask about your health. However, if the vet suspects a zoonotic disease, hopefully he/she would tell you what it is and possibly what signs for which to watch out. Providing additional information would also be useful, which is why we're developing the information sheets that are available on our Resources page). At that point, the vet would typically (and reasonably) leave it up to you to determine whether you should see your physician and what should happen from there. In the grand scheme of things, it would be very useful for vets and physicians to have some form of dialogue or at least an understanding of each other's roles and a willingness to call each other when appropriate.

Both human and veterinary medicine have a long way to go to get to the "one medicine" concept that people like to talk about. I think we’re slowly moving in the right direction, but vets and physicians need to talk more to properly cover this important area of overlap between their professions.

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ProMed recently reported about an outbreak of canine brucellosis at a "puppy farm" in Ireland. Farm is definitely the appropriate word in this case, since this operation had about 700 breeding females. The picture on the right is not from this farm, but I imagine it's a similar operation. Beyond the concerns about humane management of dogs under these conditions, such a large operation creates perfect conditions for various infectious diseases.

"The farm's owner has refused to sign an undertaking not to move the dogs off-site before an official inspection can take place to investigate the extent of the [brucellosis outbreak]."

Lack of cooperation makes any disease investigation much more difficult. It's not surprising this person doesn't want to cooperate, given the type of operation he's running.

"Someone from the farm told the Irish Times that the 2 animal welfare agencies were involved in acts of "intimidation" against the establishment."

I suspect that "intimidation" in this case means the agencies were doing their job, because I can't see how there wouldn't be significant welfare problems at a farm of this type and size.

"'We got accurate information on Friday [2 May 2009] that this man was intending moving and selling these dogs and we acted on it,' according to Jimmy Cahill, chief executive of the DSPCA [Dublin SPCA]. 'The guards  were very helpful but the owners refused to let us see the dogs or any of the carcasses.' "

The reference to "carcasses" implies that deaths have occurred. Death from B. canis in dogs is very rare but it is possible. However, a poorly managed operation with hundreds of dogs is bound to have multiple issues that could cause deaths.

Canine brucellosis is caused by the bacterium Brucella canis. This main problem with this bacterium in dogs is reproductive disease, including abortion and infertility (in both males and females). Discospondylitis (inflammation of the discs between vertebrae in the back) can also develop.

Brucella canis is a zoonotic organism. Human infections are rarely reported but it is possible that some go undiagnosed. Brucella canis can be transmitted from dogs to people through contact with body fluids from infected dogs, including urine and vaginal fluids.  The risk of transmission is likely highest when handling animals during breeding or birthing. While the bacterium can be shed in nasal secretions and saliva, levels are low in these fluids and the risks are probably correspondingly low.

One problem with preventing B.canis transmission is that infected dogs do not necessarily show any signs of disease. In people, B. canis infection can cause flu-like disease, loss of appetite, weakness, joint and back pain, vomiting and diarrhea and various other symptoms.

To control the outbreak on this "farm," quarantine and repeated testing of all dogs is needed, and positive animals must be removed from breeding. Given the information provided above, it's pretty unlikely this will happen voluntarily. I suspect this person would likely either just get rid of these dogs and get more poor-quality breeding animals, or try to continue breeding these dogs and hope people get sick of looking into his operation.

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A UK man is on a campaign to raise awareness about Toxocara, following an infection that blinded the child of a family friend. Mike Kennedy, chairman of the Grange Residents' Association, is  raising awareness about the importance of picking up "dog dirt" (i.e. dog stool).

Toxocara canis is an intestinal parasite that can be found in a small percentage (likely 2-14% in Ontario) of healthy dogs, and a larger percentage of puppies. Toxocara cati is the feline equivalent found in a comparable proportion of cats. If a person swallows an infective egg - an egg that was passed in an animal's stool and allowed to sit around in the environment for a while - infection can occur. The parasite can migrate throughout the person's body, causing various types of problems. Migration into the eye (ocular larval migrans) can cause blindness. Migration through the brain (neural larval migrans) can cause serious brain injury. These are very rare diseases, but are obviously still a concern because of they can be so severe. The risks are highest in children and people with developmental delays, since they're more likely to swallow stool, dirt, or something else contaminated with stool.

Mr. Kennedy's emphasis on educating animal owners to pick up after their pets is the key. We know a small percentage of dogs and cats shed Toxocara in their stool. You never know exactly who is shedding the parasite at any time, so removing the source of parasite eggs, the stool, is critical.  Deworming pets regularly is also important, but it is only one component of parasite control. The frequency and type of deworming needed for dogs and cats varies between regions and animals.  Your veterinarian can design an appropriate deworming program for your pet. Such a program requires a balance between adequate deworming to reduce the risk of parasites in pets (and the associated risk for human infection) and using dewormers prudently to reduce the risk of parasites developing resistance to these drugs.

Photo credit: Michael Lazarev (Clyde, the bulldog puppy)

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Recently, I made a few comments about climate change and the potential impact on infectious diseases in horses on our sister site, equIDblog. A recent news article in New Scientist discussed concerns about climate change and pets. The main infectious disease concern regarding climate change is changes in patterns and spread of insect-borne diseases, because different insect vectors may expand their normal ranges or change their seasonality in response to climate change. Some of the examples cited in the article include:

• Babesiosis, a blood-borne disease spread by the European dog tick, is being found in areas of Europe where it was previously rare.
• Increasing populations and ranges of ticks have been reported in many countries, which is a significant concern based on the number of different diseases these ticks can carry and transmit.
• Leishmaniasis has been identified in dogs in the southern UK.  If climate change allows sandflies (the insect vector of this disease) to become established in the UK, then spread of this disease could become a major problem.
• Milder winters may result in longer periods of activity of some insects that transmit disease, thereby extending the times of the year when there is a risk of disease. In some areas, year-round risk could develop for diseases that were previously seasonal.

Climate change is a complex and still rather controversial topic. Predicting the infectious diseases implications of climate change is difficult.  Information that is already available for some diseases, combined with general knowledge about microorganisms and their hosts, can help us make some educated guesses about what may happen. While the full scope of the impact cannot be predicted, it is almost certan that climate change will result in infectious disease challenges in both veterinary and human medicine.

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Quarantining animals that have potentially been exposed to rabies is a standard practice, but quarantining a whole town is new to me. Because of a large increase in rabies cases in the Flagstaff, Arizona area, a rabies quarantine was established on April 8th by the Coconino County Board of Supervisors. The quarantine requires all dogs and cats to be enclosed or secured on their owner's property. When off the property, animals must be on a leash that is no longer than six feet in length. All dogs and cats must be vaccinated, and low-cost rabies vaccine clinics have been held to help increase compliance with this requirement. Vaccination of wildlife using baits containing an oral form of rabies vaccine will also be performed. The quarantine also restricts feeding and interacting with wildlife. Also, people cannot leave pet food outside after sunset and all compost piles must be completely enclosed.

This is an aggressive approach to rabies control in an area experiencing a wildlife outbreak of the disease. They've implemented comprehensive but still quite practical measures that should help reduce the risk of exposure of domestic animals (and people) without a significant negative impact on pet owners. I've mentioned my concerns about rabies vaccine clinics in the past, but this is a situation where I think it's a good idea.

It's always hard to evaluate the effectiveness of outbreak measures, because you never know what would have happened if nothing had been done. Regardless, it will be interesting to see how well this quarantine works, both in terms of the number of new rabies cases they see and the response of citizens to these restrictions. It would be very useful if Coconino County personnel provide information about how things went when the quarantine is over - the information might be useful for management of future rabies outbreaks.

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Over 50% of households in Canada and the US have pets, and the numbers are probably similar in many other countries. Pets are often considered part of the family socially but we need to consider them part of the family biologically as well. It's clear that diseases that be transmitted between people and pets - in both directions. Unfortunately, it's also clear that physicians and vets don't do a very good job talking to each other.

Pet contact (and animal contact, in general) should be part of the standard history obtained by any physician.  In my perfect world, every medical record would include a permanent record of contact with pets or other animals. This information is potentially useful because certain diseases that are not a big issue for non-pet owners may need to be considered (or may be higher on the list of possibilities) in pet owners. Knowing about pet contacts up front could help speed up diagnosis and proper treatment.

For example:

I have a flock of rare breed sheep. The other day, I had to assist with a lambing. Contact with newborn lambs and fetal fluids is the main source of the organism Coxiella burnetti, which causes Q-fever. If I became infected, the illness would start off with vague signs like fever and malaise. If I went to a physician at that point, I'd probably be told to go home, rest and take anti-inflammatories as needed (the old "take two aspirin and call me in the morning" type thing). If the physician knew I had sheep, he/she might ask about the risk of exposure for Q-fever. Upon hearing that I had a high risk exposure a few days earlier, Q-fever would be considered right away and appropriate measures could be taken.

Also, as strange as it sounds, in my utopian world physicians would ask about pet health. Yes, it may seem strange if your doctor were to ask "So how are you doing today? And how's your dog been feeling lately?" - but it might be important. Illness in your pet may be associated with illness in you or other members of your household. Knowing that a pet is sick might give some indication of that (a) certain disease(s) are more likely in a person. Also, if the sick pet has been to a veterinarian for testing, those results might be useful to the physician. There's no guarantee that a pet and owner that are sick have the same thing, but a general principle of medicine is that a single cause is more likely than co-incidental independent problems.

For example:

Similar to the case of psittacosis in a pet store employee that I reported about recently, let's say that you own a bird and it's been sick for a week or so. It's weak and not eating well. You then come down with a fever and cough - something that's not uncommon. However, when your astute physician asks about the health of your pets, he/she gets concerned about the fact that your bird is sick. Your doctor contacts your bird's veterinarian, and it becomes clear that the bird could be infected with Chlamydophila psittaci, the cause of psittacosis in people. Your doctor therefore puts psittacosis on top of the list of potential problems, and instead of telling you to go home and rest, he/she takes some blood samples to try to diagnose it the infection and may even start treatment right away. Because your physician identified a higher risk situation with your sick bird, you get prompt treatment, you start to feel better in 24 hours and it's unlikely you'll have any major problems. (The mortality rate from psittacosis is < 1% in people that are treated properly. If the diagnosis is missed, the mortality rate increases to 20%, and you also run the risk of complications such as heart valve damage.)

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Helicobacter species are a fascinating group of bacteria. They live in the stomach of humans and many animals, an environment that was previously thought to be completely inhospitable to bacteria. We now know that Helicobacter bacteria are beautifully adapted for survival in the stomach and are very common. In people, Helicobacter pylori is an important cause of gastritis (inflammation of the stomach), stomach ulcers and stomach cancer.

Studies looking at bacteria in the stomachs of dogs and cats have found that Helicobacter species are extremely common, with some studies finding one or more species of Helicobacter in every dog or cat that was tested. Since Helicobacter is an important problem in people, does that mean that we need to be worried about pets as a source of infection? Probably not.  Here's why:

It could be a problem because:

• A few studies have found the same Helicobacter species in infected people and their pets.

It's probably not a problem because:

• Studies looking at risk factors for Helicobacter infection in people have not identified pet ownership as a risk factor.
• A study comparing one Helicobacter species that has been mentioned as a possible zoonotic concern, H. heilmannii, reported that H. heilmannii strains from people were generally different than those from animals.
• While other Helicobacter species are common in dogs and cats, H. pylori (the main cause of problems in people) is rare in pets.
• While finding the same Helicobacter species in a person and his or her pet raises concern, studies have yet to demonstrate whether such findings are due to animal-to-human transmission, human-to-animal transmission, or infection of both person and pet from the same source.

Overall, the risks of pet-associated Helicobacter infection are probably very, very low. If there is any involvement of pets in this disease in people, it's probably sporadic at most. Avoiding contact with stool from pets and paying good attention to handwashing should decrease the risk even further.

One question that is currently unanswered is whether the mouth of a dog or cat can be a source of Helicobacter infection, because the bacterium can be found in saliva. We really don't know whether this is a risk - it's probably minimal at most, but avoiding contact with pet saliva (e.g. no sloppy wet dog kisses!) is a good idea anyway.

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ProMed mail reports two more rabies fatalities in an ongoing outbreak in Bali, Indonesia.  The first person was bitten by a stray dog, which always must be considered a potential rabies exposure, especially in an area where an outbreak is underway. He received one rabies shot but did not undergo the whole post-exposure series because of a fear of needles, and he died.

The second person was bitten by both a stray and a pet dog, another clear indication for post-exposure treatment. She refused treatment because of a fear of needles, and also died of rabies.

These were two completely preventable deaths. The decision to forgo treatment almost certainly cost these people their lives - rabies is preventable with appropriate and timely post-exposure treatment. These cases also highlight the need for proper education of the public when it comes to rabies, both in terms of avoiding strays and the need for prompt attention when there's potential exposure to the disease. I have no idea how forcefully medical or public health personnel explained the need for proper treatment. For people that want to decline treatment, aggressive and comprehensive education is needed. Ultimately, people are allowed to make bad decisions, but we need to make sure they at least make informed bad decisions.

There are various other concerning issues with this outbreak, particularly the government's response to it. Multiple sources have apparently advised the government that aggressive vaccination and halting of dog movement between the peninsula and the mainland could contain this outbreak. So far, this has not been done. Amazingly, importing rabies vaccine into Bali was illegal until December 2008, and it is still illegal to vaccinate dogs outside of the outbreak area! The cost of vaccination has been used as an excuse not to do so. Certainly, financial issues are important in developing countries. However, the estimated cost is only about $0.50 US per dog. When one considers that this area is highly dependent on the tourist industry, they need to consider this as an investment to maintain their economy. Would you like to spend your vacation in an area with an ongoing rabies outbreak?

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I guess there's now a week for absolutely everything. aPaws, the Association of Professional Animal Waste Specialists (no, I'm not making this up) has declared April 1-7 to be International Pooper Scooper Week. The overlap with April Fool's Day is apparently just a coincidence.  This group was formed in 2002 in recognition of "the growing problem in our communities, environment and water tables" associated with, yes, dog poop.

The American Pet Association estimates that over 4.4 billion pounds of poop are produced by the some-71-million dogs in the US each year. That's enough to cover 900 football fields with 12 inches of dog waste. (That is some deep do-do!)  Dog feces can contain a wide variety of bacteria and parasites, some of which can infect other dogs, and some of which can also infect people. The risk to people and other animals is greatly reduced by prompt removal of feces and proper disposal (i.e. stoop and scoop). It's a pretty simple concept: if your pet poops outside, pick it up. Use a plastic bag, seal it, deposit it in the garbage, then wash your hands (or use an alcohol-based hand sanitizer if you're out for a long walk and there's no sink handy). Most people are conscientious about this, but one look around most parks will show you that not everyone is (and unfortunately that can give those of us who do stoop and scoop a bad name!).

Photo source: http://www.freewebs.com/pooridder/

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I know this doesn't relate to infectious diseases, but it's still an interesting pet-related public health topic. The latest edition of the CDC's Morbidity and Mortality Weekly Report has a article entitled "Nonfatal fall-related injuries associated with dogs and cats - United States, 2001-2006". It contains some rather interesting information. Among the highlights:

• Based on their data, they estimate that an average of 86 629 people are injured from falls associated with dogs and cats every year. Over 26000 fractures occur.
• Injuries were most frequent in people 0-14 and 35-54 years of age, but fractures were most common in people over 75 years old. Women were 2.1 times more likely to be injured than men.
• 88% of injuries were associated with dogs.
• Most of the injuries (62% from dogs, 86% from cats) occurred at home.
• Walking and chasing pets were the most common activities associated with injuries. Falling or tripping over the pet was the most common cause of injury, followed by being pushed or pulled over by a pet.
• 11% of injuries associated with cats occurred when someone was chasing a cat. (I can relate to that, because I almost fell down the stairs once trying to catch my cat after he'd stolen an entire roast off the kitchen counter!)

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A dog park was closed because of an attempt by a dog-owner to disinfect puddles.  The woman was seen pouring a gallon of bleach into a mud puddle, sparking an investigation. The site was closed while city staff pumped out puddles. The woman told the person that witnessed and reported the incident that her dog had contracted the intestinal parasite Giardia in the park, and she was trying to sanitize the water.  However, authorities believe it may in fact have been a malicious act (i.e. an attempt to poison the dogs using the park).

• Firstly, there's no way the woman could know that the park (let alone a specific puddle) was the source of her dog's infection. Giardia can be found in the environment and in the stool of a small  percentage of healthy dogs (~7% in many studies).
• Secondly, pouring a toxic substance into the puddles in the park is obviously not an appropriate response. Bleach is a good disinfectant when it's used right, but disinfecting outdoor surfaces like this is essentially impossible. Organic debris (e.g. mud) will readily inactivate bleach, but the bleach could still make an animal sick if too much (too high a concentration) is swallowed, because it's very caustic.
• Thirdly, for this woman to take matters into her own hands like this without consulting  someone who knows something about infectious diseases, and potentially exposing a lot of animals to high levels of bleach is irresponsible. If there was concern about the park as a source of infection, the appropriate response would have been to talk to city staff.

In reality, the risk to other dogs was probably pretty low. It’s pretty obvious when there's a lot of bleach somewhere (even just based on the smell), and in general dogs would probably be very reluctant to drink bleach-contaminated water.

One officer stated that he suspects the Giardia story was an excuse contrived by the woman when confronted by the passer-by who witnessed the bleaching incident. That’s certainly possible, but I’m surprised someone would come up with a specific excuse like Giardia.  If the woman is found, that should be easy to figure out - the diagnosis would have to be in her dog's medical record.  Police stated that the woman, if identified by the authorities, could potentially face animal cruelty charges. I think that’s pretty unlikely, considering what usually has to happen for someone to actually be charged and convicted of animal cruelty. I suspect this really was an overzealous response by someone who lacks common sense. There was no comment about whether the woman would be billed for the city staff time required to deal with the clean up - that might be a more effective deterrent to similar incidents in the future!

Parks are inherently a high-risk environment for exposure to infectious diseases. Whenever you mix large numbers of animals, especially in an area where they often pass stool, there is an increased risk of disease transmission. You have to accept that when going to a park. People should also ensure that they never take a sick animal to a park, promptly clean up stool, and may sure that their pet is on an appropriate vaccination and deworming program. Disinfection of a park will never be part of the infection control program.

More information about Giardia can be found on the Worms&Germs Resources page.

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Headlines can sometimes be very misleading. The title of this post is from a news article that implies that rabies is a foodborne disease. The first sentence of the article states:

"A new study has detailed how two people in Asia contracted rabies after eating dog or cat meat."

This is a prime example of why it is so important to read more than just the first few sentences of any article, and ideally find the original source of the information. The article refers to a paper in PLoS Medicine. The paper describes two cases of rabies in men from Hanoi, in Vietnam. One had no known history of an animal bite or other rabies exposure, while the other had been bitten a month before becoming sick by a non-rabid dog (the dog was still healthy when the man developed rabies - if the dog had been rabid at the time of the bite it would have died within two weeks). Both patients had butchered and eaten either a dog or cat, including the brain, within 3-8 weeks of becoming sick.

• The first patient had butchered and eaten a dog that had been killed in a traffic accident. He took out the dog's teeth before butchering it, thinking that this would protect him if the dog had rabies (because rabies is so often associated with bites, he likely didn't realize the virus is actually in the saliva and brain tissue).  The skull was opened to remove the brain.  The man wore work gloves, and didn't report any injuries during butchering.  All parts of the dog that were eaten were cooked first.  No one else that ate any part of the dog got sick.
• The second patient had butchered and eaten a sick cat that had been acting abnormal for a few days. Again, all parts of the cat that were eaten were cooked first, and no one else that ate any part of the cat got sick.  However, the man who developed rabies had prepared the cat's brain for cooking using his bare hands.

In both cases, the affected people were exposed to animals that were sick (cat) or may have been sick (dog hit by car). Only the people who butchered the animals got rabies, while no one else who ate the animals got sick. It is most likely that the two men were exposed to rabies virus during butchering, through contact of infected nervous tissue (e.g. brain) with any tiny bit of broken skin, or even possibly the eyes, nose or mouth, before the tissue was cooked.  In Vietnam, butchering  (not eating) dogs is a recognized risk factor for developing rabies.  It is extremely unlikely that eating cooked meat from a rabid animal would result in transmission of rabies to a person.

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A large outbreak of rabies continues to have devastating effects in Angola, Africa. While rabies outbreaks are not uncommon in some parts of the world, the number of people affected in this outbreak is remarkable. A hospital in Luanda, the nation's capital, has diagnosed rabies in at least 93 children in the past 3 months. All have died. The main source of the disease in this case is Angola's large stray dog population. Stray dogs can transmit rabies to other dogs and people through bites. The poor socioeconomic status of the country increases the risk of outbreaks like this because:

• Vaccines are not readily available (for dogs or people)
• It is difficult to organize and fund vaccination programs for stray dogs
• It is difficult to educate the general population about how to avoid and manage rabies exposure
• The healthcare system is relatively limited

These problems, all related to a poor economy, create a "perfect storm" for a rabies outbreak. The shortage of human rabies vaccine and the high cost of post-exposure prophylaxis (PEP) makes it much more likely that people will actually develop signs of rabies after being exposed. The cost of PEP is more than the average Luanda family makes in a month.

Fortunately, the outbreak seems to be waning. However, without improvements in stray dog management (including vaccination) and access to adequate PEP, future outbreaks and problems are inevitable. It was reported that "adequate" supplies of canine rabies vaccine are now available. Hopefully, a concerted effort to vaccinate as many dogs as possible will reduce the rabies load in the canine population, thereby helping to decrease the risk to the people living in the area as well.

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This rather sensational title is from a Murdoch University (Australia) news article regarding a study of intestinal parasites in Australian dogs. It certainly grabs one's attention. For me, the article brings to mind two different trains of thought:

1) Far more than 10% of dogs could make their owners sick.  Be it dogs, cats, rabbits, iguanas or anything else, every pet is carrying something that could cause an infection in a person in certain situations. If a study says that only X% of dogs/cats carry some sort of zoonotic pathogen (and X isn't 100), then they didn't test hard enough or they didn't test for enough things. Every animal - and every person - is carrying something that can make others sick. However, even though all pets carry zoonotic pathogens, most of these are of minimal concern to most people, and therefore the likelihood of most pets making their owners sick is relatively low. We have to remember, however, that there is no such thing as "no risk" pet contact, just as there's no such thing as "no risk" contact between people.

2) The 10% figure from this study refers to the percentage of dogs that were shedding the intestinal parasite Giardia. This parasite can cause disease in people and that's why there is concern. However, the 10% figure isn't really surprising, as the press release states, because previous studies from different areas in the world have reported Giardia shedding by 7-10% of healthy dogs. The real question is, what is the risk to people from these dogs? The short answer is: we don't know. Not all types of Giardia found in dogs are able to cause disease in people. Figuring out what type of Giardia a dog is shedding requires fairly specialized testing, and there's no indication that this was performed for this study. If most dogs carry strains that don't infect people, then the risk is very different than if most dogs were carrying zoonotic strains.  Furthermore, we don't know how often Giardia is transmitted between people and pets in any situation. At this point, there is actually very little information regarding transmission of Giardia from pets to people. That being said, it's better to err on the side of caution and assume that Giardia could be transmitted from pets to people, at least until we have good evidence otherwise.

I'm not trying to dismiss the potential concerns about Giardia in dogs, nor do I think the study isn't useful. It's an interesting study that has provided new information about intestinal parasite carriage in dogs in Australia. However, it doesn't really tell us anything new about the risk to humans.

Professor Andrew Thompson, Murdoch's Head of Parasitology gives some good advice when he states "As a result of these new findings, dog owners should be aware of the signs of Giardia and how to prevent infection in their pets. If you suspect that your dog may be infected with Giardia, it is important you visit your local vet for a full diagnosis.”

More information about Giardia can be found on the Worms&Germs Resources page.

Photo: Giardia trophozoite (CDC Public Health Image Library #8698/Janice Carr)

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I read a press release today entitled "New Parasite Infection Killing Pet Dogs in Southern England". It's about the lungworm Angiostrongylus vasorum. The main reservoir for this parasite in England is the common red fox. Slugs and snails are involved in transmission of the worm as well.  Infection of dogs most likely occurs through ingestion of the parasite from contaminated water or other environmental sources. The press release mentions a study that was released last year which reported an increase in the parasite in wild foxes. It mentions (without providing any data) that infections are occurring regularly dogs in some regions. This may well be true but brings to mind an important point I mentioned the other day (among others): know the source of information you are reading. I know I'm being a bit cynical, and it's possible that they have the well being of pets in mind, but the press release is from an online veterinary pharmacy, a company that obviously benefits from increased treatment of pets with dewormers.

This is made clear by their statement "Luckily there are a number of medicines available that can provide real and lasting protection from this nasty parasite. At www.vetscriptions.co.uk we recommend that all dog owners make it their business to find out about this disease and make sure that their dogs are fully protected."

Is lungworm a real and increasing threat in the UK? It's certainly possible. I don't dismiss the possibility at all.

Would I get concerned about it at this point? No. I'd look for objective information and ask my vet if there are any concerns in my particular area. Like the press release says, people should "make it their business to find out about this disease."

So what does this tell me? It reminds me that there are a lot of potential infectious disease threats out there that I need to pay attention to, but there are also a lot of people trying to make money at the same time. It could be that this company is being benevolent and honestly trying to make sure that pet owners are aware of the risks of lungworm. It's also possible they are taking advantage of a marginally relevant problem. Information like this is good for raising some questions, but getting advice from a non-biased source is critical.

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I used the think the New York Times was a reputable newspaper and source of reasonable information. However, considering some of the articles I've seen, I no longer have a good opinion of this newspaper. One example from a few years ago came across my desk recently.  The article is basically an infomercial for an unqualified person that sells pet health products.  The person in question is an industrial designer by training - you'd think a reasonable news source would look for someone with training in veterinary medicine, nutrition or pharmacology when discussing pet health. (Given the level of expertise they require, I guess I'm qualified to comment in the New York Times about how to solve conflict in the Middle East or fix the economy). Among some of the gems in this article are:

• People "have to include raw and whole foods in their pets' diets..." and "[Pets] don't get E. coli or Salmonella." Tell that to the dogs and cats that get sick and die from Salmonella. I can't believe people that sell raw foods continue to falsely claim that pets can't get Salmonella. Outbreaks of salmonellosis associated with raw foods have been reported. Dogs have even been sickened in the recent peanut butter Salmonella outbreak.
• The big problem with the pet food industry is that people treat pets like televisions and get a new one if they're sick. Apart from the last part being ludicrous, what does that have to do with the pet food industry?
• The alley dogs this guy grew up with in the Bronx lived a long time.  Now, a dog is considered old if it lives past 7 years. Show me any evidence that feral dogs live longer than household pets. Not a chance.
  
• Pets are dying younger because of low grade nutrition and pharmaceuticals. Again, show me evidence that pets are living shorter lives. I'm certain it's the exact opposite.

People need to make sure that they critically assess things that they read about pet health and diseases. Just because something is written in a high profile newspaper doesn't mean it's necessarily correct. In the internet era, volume overload and differentiating good sources from bad sources can be difficult. Here are some tips:

• Look for advice from qualified individuals. That's not a guarantee, but I'd rather have my car fixed by a mechanic than a gardener.
• Beware of advice from people that are in a conflict of interest, such as people selling a product. For most reputable companies, representatives can be sources of good information, but unfortunately it's not always true.
• Ask your veterinarian about questions relating to animal health and nutrition.
• Use common sense. If something seems too good to be true, it probably isn't. Something that claims to cure all that ails you probably cures nothing.

A rebuttal to this article can be found here.

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A park in Orange County, Florida has been closed because a dog with canine parvovirus was found in the park.  Canine parvovirus is a potentially serious infection in dogs (mainly puppies) that can cause severe vomiting and diarrhea. In some cases, it can be fatal.  Proper vaccination against parvovirus is critical for puppies. In Orange County, they have closed the park because of concerns about parvovirus transmission. The have also apparently "bleached the dog park".

Parvovirus can live for a very long time in the environment, however disinfecting an outdoor environment is not only impractical, it's impossible! We can disinfect clean, smooth surfaces like sealed ceramic floors and smooth countertops, but we can't disinfect outdoor environments with permeable, porous surfaces and abundant organic debris (dirt). Bleach is not active in the presence of organic debris, and porous surfaces allow bacteria and viruses to escape contact with disinfectants. So, while it's good to see that they are concerned about disease transmission, this particular aspect of their control efforts isn't going to be effective.

Parvovirus exposure is an ever-present risk in areas where multiple dogs congregate. The virus can be shed in the stool of even healthy-looking dogs. In this situation (like all others) the emphasis should be on keeping high-risk dogs (e.g. unvaccinated puppies) out of these areas, not closing the park altogether and attempting to disinfect it. Parvovirus vaccination is very effective, and properly vaccinated adult dogs are quite low risk. Prompt removal of stool by dog owners helps reduce the risk further by decreasing the risk of environmental contamination. Therefore, the three most important control measures are:

• Ensure puppies are properly vaccinated.
• Keep puppies out of areas visited by numerous dogs until they have been fully vaccinated.
• Scoop poop.

And since the focus of this site is zoonotic diseases, remember that canine parvovirus is not transmissible to people.  Human parvovirus infection (Fifth disease) is caused by a completely different virus.

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I received the following question from a reader the other day: "I'm currently pregnant and was bitten by my grandmother's German Shepherd.  The bite was on my ankle and broke the skin in several places.  I went to the doctor and was prescribed antibiotics and the wound has seemed to heal fine.  This is my second pregnancy and I have been diagnosed as group B strep positive, which I wasn't with my first child.  I know that dogs can't spread strep throat to humans, but is it possible that I picked up group B strep from the bite?"

The short answer is that it's extremely unlikely there's an association.

Group B Streptococcus is predominantly a problem in people. Most people that carry this bacterium have no problems, although it can cause infections in some situations. It is of particular concern in pregnant women, because in 1-2% of exposed newborn babies the bacterium can cause serious infections such as bloodstream infections, meningitis and pneumonia. That is why pregnant women are often screened for Group B Streptococcus shortly before their due date, by taking a swab from the vagina and rectum. Approximately 10-30% of pregnant women carry Group B Streptococcus. Pregnant women that are carriers are usually given antibiotics shortly before delivery to reduce the risk of infection of the baby.

What about the role of pets? Group B Streptococcus is mainly found in people, and is quite common in healthy people. It is rare in pets, although it can cause various types of infections in animals too. Group B Streptococcus infections in dogs might actually represent human-to-dog transmission, although this hasn't been proven. In the case described above, a dog bite on a person's leg would not be a high risk for transmitting this bacterium to the intestinal tract or vagina. If a dog was carrying this bacterium in its mouth, it could cause a bite wound infection, but it is very unlikely that the bacterium would spread to other parts of the body in a healthy person.  Other bacteria in the dog's mouth would be more likely to infect such a wound, even if Group B Streptococcus was present.  If dogs were common carriers of this bacterium (which they are not), the main risk of transmission would be from regular contact, not bites.

So don't blame the dog... at least not for the Group B Streptococcus. The bite itself is another issue.

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One of my favourite stories about surgeons comes from a book by Irwin W. Sherman called "The Power of Plagues." In the pre-anesthesia and pre-antibiotic era, speed was considered the sign of a good surgeon. One surgeon, Robert Liston, was particularly renowned for his speed. However, speed sometimes lead to problems. In one surgery, he amputated a leg in 2.5 minutes, but the patient died of infection after surgery (a common event those days). During surgery, he accidentally amputated the finger of his assistant as well, who also subsequently died of infection. To top it off, he slashed the coattails of a surgeon who was watching, who "died of fright" thinking his organs had been slashed too. He's the only surgeon on record with a 300% mortality rate for a surgery.

These days, surgery is a lot more humane and safe. However, problems like surgical site infections still occur. They occur following a much smaller percentage of surgeries than they used to, but they can still be very serious.  Nowadays, more of these infections are being caused by multidrug resistant bacteria, which can affect and be transmitted between both animals and people. It's been stated that the time of maximal influence on surgical site infections beings and ends in the operating room (e.g. the most critical time for preventing infection is during the surgery itself).  However, there are things that can be done at home to help reduce the risk of infection.

• Antibiotics are usually NOT required after surgery, depending on what procedure was performed. But, if antibiotics are prescribed by your veterinarian, make sure you give the full course and follow all instructions carefully.
• Keep your pet from licking the surgery site. Trauma from licking and chewing, and bacteria from the mouth can help start an infection. If your pet is licking or chewing its surgery site, consult with your vet about ways to stop this.
• Keep an eye on the surgery site. If you see signs of infection such as excess heat, pain, redness, swelling or discharge from the site, talk to your vet as soon as possible.
• Don't touch the surgery site. You could contaminate the site with bacteria from your skin that could start an infection. Also, if an infection is present, bacteria could spread to you.  If you must touch the surgical site (e.g. if you need to change the bandage over it, or your veterinarian has instructed you to clean the site), you should wear disposable gloves.

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If your veterinarian suspects your pet may have ringworm, there are several different ways he or she may test for the causative fungus (a dermatophyte) on your animal's fur and skin.  Some of these techniques are more useful than others in different situations.

• Wood's lamp:  A Wood's lamp is simply a special ultraviolet light.  Approximately half of all Microsporum canis strains (the most common species of dermatophyte that causes ringworm in cats and dogs) will fluoresce blue-green under such a light. This type of testing is obviously very easy to perform.  However, other debris in an animal’s hair coat may fluoresce as well, and other species of fungus that cause ringworm do not fluoresce, so this test is not useful by itself in most cases.
• Microscopy: Sometimes ringworm fungus can be seen on hair shafts from an infected pet when examined under a microscope.  However, it is easy to confuse other debris and structures for dermatophytes.  Also, not every hair on an infected animal will carry the fungus, so it's possible to miss the infected hairs altogether with this test.
• Fungal culture: The best way to diagnose ringworm is to culture the fungus from the infected individual (person or animal). In animals, one of the best ways to collect a sample for culture is to comb over all the fur and skin with a new toothbrush, and then try to grow dermatophytes from the toothbrush. This allows the fur from all over the animal to tested, rather than just one little clump of fur plucked from one area.  It can also make it easier to get a sample from the face and paws of cats, which is where these animals often carry the fungus.  Although fungal culture is the best way to diagnose ringworm, remember that fungal culture takes much longer than bacterial culture – instead of days, it may take up to three weeks to grow some dermatophytes.

It's also important to remember that dogs, and more often cats, may carry dermatophytes on their fur even when they look healthy.  A positive fungal culture from an animal with skin disease, particularly a cat, does not necessarily rule out other diagnoses, so your veterinarian may still recommend other tests as well.  However, any animal with ringworm should be treated to prevent spreading the infection to other animals and people.

More information about ringworm is now available on the Worms&Germs Resources page, and in our archives.
 

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"Some Beach, Somewhere" is not only a popular country music song AND the name of one of the best Standardbred racehorses in the world (originally Canadian, no less!), it's also the prime source of infection for a disease called cutaneous larval migrans.

Cutaneous larval migrans is a skin disease caused by migration of hookworm larvae. The most common hookworm species involved is Ancylostoma braziliense, which can be shed in the stool and dogs and cats. Ancylostoma caninum  and A. tubaeforme are other species of hookworms that parasitize dogs and cats, respectively, and can also cause the disease, but much more rarely.

Animals infected by the hookworms shed hookworm eggs in their stool. These eggs then develop into larvae, and people become infected through skin contact with hookworm larvae in the environment, particularly in sandy areas like beaches where infected animals may have defecated.

Cutaneous larval migrans is characterized by a "serpiginous (snake-like) rash" that is intensely itchy (see picture left).  This is caused by the parasite larva burrowing through the skin. In North America, the disease is most common in the southeastern US and the Caribbean. Most , if not all, cases in people in Canada are associated with travel, especially to Caribbean countries; they presumably caused by exposure to hookworm larvae on the beach. Ancylostoma braziliense is not found in Canada.

The best means of controlling cutaneous larval migrans are to promptly remove dog and cat stool from the environment and dispose of it in the garbage, and to regularly deworm dogs and cats. This is important in areas where A. braziliense is endemic, but is easier said that done in areas where feral (wild) dogs are common.

Photo source: http://www.leeds.ac.uk

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I've had this question a lot lately. Methicillin-resistant Staphylococcus pseudintermedius (MRSP), which is sometimes misidentified as methicillin-resistant S. intermedius (MRSI), is an important and increasing cause of infections in dogs and cats. After an animal has had an MRSP/MRSI infection, a question people often ask is how long they will carry the bacterium?

MRSP can be carried in the nose, intestinal tract or on the skin of a small percentage of normal animals. The implications of this are not clear, but it is reasonable to assume that carriers are more likely to develop infections in certain situations (e.g. if they sustain a wound or need to have surgery), and can transmit it to other animals (and possibly people, but that's much less of a concern with MRSP than with MRSA).

Back to the question... To be perfectly honest, we really don't know. However, I think it's reasonable to assume that some animals could carry MRSP for a long period of time - certainly weeks or months, maybe even years. Staphylococcu pseudintermedius is a common bacterium in healthy dogs and cats, and has basically evolved to survive on these animals. The methicillin-resistant versions are likely no different in this respect, so it's reasonable to assume that some animals could be long-term carriers. This makes controlling MRSP more difficult.  In contrast, MRSA appears to be only transiently carried by dogs and cats, probably because it is better adapted to living on humans than pets.

What you should do in the meantime if your pet has MRSP:

• Treat any infection as per your vet's instructions.
• Always complete the full treatment course.
• Wash your hands after contact with your pet, healthy or not.

More information about different types of staph bacteria can be found in the previous Worms&Germs post entitled Methicillin-Resistant Staph - What's In A Name?

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I'm sure you've heard about the large outbreak of salmonellosis in people in the US associated (again!) with contaminated peanut butter. Based on the extent of the outbreak, it probably should not come as a surprise that p