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've written a few times in the past about the need for better definitions and guidelines for service dogs. Service animals are incredibly beneficial for some people, but there is great potential for abuse of the "service animal" designation by people who don't really need a service animal and/or are using completely untrained and sometimes inappropriate animals.

An example of such unscrupulous behaviour is RegisteredServiceDogs.com. At this site, you can enter your pet's name and your information, and get a form for your physician to sign requesting the dog be authorized as a service animal - but there is no such process, and this company has absolutely no authorizing power! Additionally, there's a place for a vet to sign affirming  that the dog being "registered" has had all shots required by the state and that, to the best of the vet's knowledge, it will not be a threat to the general public. There is no mention about whether the dog is healthy, is well-trained, is specially trained as a service animal, has undergone any real scrutiny to determine whether it could be a "threat to the general public", or anything else that should be a requirement for a true service animal. In other words, this company does absolutely nothing to ensure that the animal is an appropriate service animal. For their overwhelming effort of providing you with a form to fill out, they charge $49.95 to send you a worthless card saying your dog is a "registered service animal".

Anyone who has a real service animal has no use for a card such as this. If they run into someone who inappropriately tries to restrict their access, they're better off with information from the agency that trained the animal or, in the US, a copy of highlights of the ADA, since restriction of service animals is illegal.

If this company was really in it to help the cause of service dogs, it would have some standard criteria to ensure that the animals it certifies as service dogs are really service dogs. Otherwise, it's a money-grab to provide a useless card to people with true service animals, and a way to help people who just want to take their pets with them to places where they are banned. None of this helps the cause of true service dogs.  It is a disgrace.

Anyone with a service dog that has questions or concerns about access should contact the agency that trained their dog or another reputable (non-profit) source of information such as Delta Society.

Image source: www.guidedogsofamerica.org

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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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A report from Seattlepi.com is a textbook example of what can happen to certain people after dog bites. Mike Moore tried to break up a fight involving his two dogs and received a minor bite. It barely broke the skin. No big deal, eh? Well, perhaps for most people, but unfortunately not for Mr. Moore.

He cleaned the wound and didn't think much about it. Two days later, he thought he had the flu. The next day, he was worse and went to the hospital. By the time he arrived, "his face and body had a bluish tint" ...never a good sign. When he was being examined, he was asked about the scar on his abdomen and he told the hospital staff it was from his spleen having been removed. They then asked about the bandage on his hand and he mentioned the dog bite. (Insert big ringing bells here!) The article says that the medical staff couldn't pinpoint the problem right away, but hopefully Capnocytophaga was a leading thought. Mr. Moore was critically ill by this point with multiple failing organs. He was admitted to ICU, became septic (overwhelming infection in his bloodstream) and was put on a ventilator. His hand had to be amputated, as did both legs below the knee and three fingers on the remaining hand.  But he survived. (Despite the obvious long-term problems, he's very lucky to be alive after such a severe infection).

People that have had their spleens removed or who have non-functional spleens are at much greater risk for various infections, such as Capnocytophaga infections. No one should be allowed to leave a hospital after having their spleen removed without a letter saying, among other things, if you are bitten by a dog, get thee to a physician (pronto)! If you don't have a functioning spleen, make sure you know the risks and how to protect your health. 

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

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Just when all those turkeys that managed to survive Thanksgiving weekend thought their troubles were over, there's new issue: H1N1 influenza (formerly known as swine flu) has been found in an Ontario turkey flock.  The H1N1 virus was first reported in birds in Chile in late August.

This is not a reason to panic.  No one can get the flu from eating a properly-cooked Thanksgiving turkey (nor from any other type of properly-cooked turkey).  The producer has voluntarily (and very responsibly) quarantined the affected flock, and no birds or eggs have left the facility.  There is no risk to the food chain.

Pigs can be infected by human, pig and bird flu viruses, and multiple infections can result in viruses trading genes and producing new viruses that can infect more species.  So it's not too surprising that H1N1can infect people, pigs and now birds as well.  This incident serves as an important reminder that we need to remain diligent about infection control and hygiene, even around animals.  It's highly unlikely that these turkeys had contact with infected pigs - most likely the virus was spread to this flock by a person.  Poultry producers may therefore need to consider getting vaccinated for H1N1 flu not only to protect themselves, but also their flocks, and anyone who may have the flu should definitely stay off these farms.  Hopefully the virus does not become established in wild bird populations (like H5N1 has in some areas), as this would make it much harder to control.

Recommendations for avoiding the flu (H1N1 or other) remain the same:

• Wash your hands and/or use alcohol-based hand sanitizer
• Sneeze into your elbow
• Disinfect commonly touched surfaces
• Stay home if you are sick
• Get vaccinated!

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You'd think, after countless outbreak of salmonellosis associated with pet turtles, that people would learn and things would start to improve. I guess not. A paper published this week in Pediatrics (Harris et al) described a large outbreak of Salmonella Java associated with pet turtles. Between May 2007 and January 2008, 107 infections were identified. The median age (the age in the middle of the range of affected people) was seven years old. Sixty percent of infected people reported exposure to turtles during the week before they got sick; 87% were small (<4 inch) turtles, and 34% were purchased at a retail store (despite the fact that the sale of turtles less than 4 inches long is banned in the US). Five infected people, all less than 10 years of age, reported kissing the turtle or putting it in their mouths.

When they compared people with Salmonella Java infection to people without the infection, 72% of people with Salmonella reported contact with turtles versus only 4% of controls.

Salmonella is far from rare but it's nothing to ignore. Thirty-three percent of infected people were hospitalized. Fortunately, no one died.

The link between turtles and Salmonella has been known for a long time. Healthy turtles can carry the Salmonella bacterium and be a source of infection, particularly for children. The sale of small turtles is banned in the US to reduce the likelihood of close contact between turtles and kids, but this law is widely flouted. An understanding of the link between turtles and Salmonella is surprisingly uncommon - only 32% of Salmonella patients in this study (and 28% of controls) reporting knowledge of this link. Clearly, there are a lot of areas which could be improved.

• If banning the sale of small turtles is truly an effective measure, then it should be enforced. "Black market' turtles are far too easy to find.
• More public education is needed, among the general population and particularly people buying turtles. You shouldn't be able to take a turtle home from a store without an information sheet about the risk of Salmonella and how to avoid it.
• People with turtles (or any reptile) need to recognize the risk and act appropriately. Good general infection control and hygiene measures are needed to reduce the risk of Salmonella exposure.
• Households with children under five years of age, or with immunocompromised individuals should not have pet turtles.
• Antibiotics are not the solution. Attempts to create Salmonella-free turtles with drugs have just led to the production of turtles carrying antibiotic-resistant Salmonella.
• Common sense needs to be a little more common. The picture above (from http://www.familylovezone.com/js_DeepAndWide.htm) was proudly posted by a parent.

More information about infectious disease risks associated with turtles can be found on the Worms & Germs Resources page.

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When I talk about methicillin-resistant Staphylococcus pseudintermedius (MRSP), I usually say that the human health risks are low because human infections are very rare. However, rare doesn't mean it can't happen, as demonstrated by a case report entitled "Beware of the Pet Dog: A Case of Staphylococcus intermedius Infection" published in the American Journal of Medical Sciences (Kempker et al 2009).

This paper reports about a post-operative sinus infection in a 28-year-old woman. Cultures were taken and the bacterium was initially misidentified as a coagulase-negative Staphylococcus. It was then misidentified as S. aureus, and finally determined to be S. intermedius. In reality, that's probably another misidentification because the bug almost certainly was truly S. pseudintermedius. (It's become clear over the past couple years that S. intermedius is basically non-existent in dogs and that what has been called S. intermedius in the past is truly S. pseudintermedius).

It's important to remember that human infection with S. pseudintermedius is a rare event. Whenever you see a single case reported, you know it's a pretty uncommon or novel event. Further, this was a post-operative infection, not a spontaneous infection occurring in a low-risk person. At the same time, we need to make sure we don't completely ignore the potential risks. While the risk of transmission of S. pseudintermedius (including MRSP) seems to be very low, we shouldn't ignore it completely. Isolation and other strict measures aren't indicated when dealing with a pet with S. pseudintermedius infection, but general attention to basic hygiene practices and avoiding contact with the infected site is still a good idea.

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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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Clostridium difficile is a high-profile bacterium, being an important cause of illness and death in people. It can also be found in various animal species, including dogs and cats. In a study we published earlier this year (Lefebvre et al, Journal of the American Veterinary Medical Association, 2009), factors associated with acquisition of Clostridium difficile by dogs involved in hospital and non-hospital therapy programs were assessed. Things that were significantly associated with a dog acquiring C. difficile were:

- Contact with human hospitals: Not too surprising since it's clear that hospitals can be highly contaminated with C. difficile and the hands of some patients petting the dogs are probably also contaminated.

- Contact with children: Most parents know that kids are biohazardous (we've getting over a round of illness in our house brought home by the kids - not an unusual event). Whether the increased risk for dogs is because kids have higher rates of C. difficile carriage, or because they have closer contact with dogs (with little hygiene) or some other factor isn't clear.

- Recent use of antibiotics: No surprise here. Antibiotic use is a well-recognized risk factor for C. difficile, since antibiotics can disrupt the normal protective bacterial population of the intestinal tract and allow C. difficile to grow.

- Recent use of antibiotics by a person in the house: I think this is a fascinating result and a great example of the close inter-relatedness of people and pets microbiologically. What presumably happens is that when someone is treated with antibiotics, they are more likely to acquire C. difficile and pass it in their feces. By doing so, there is a greater chance that their dog will be exposed to C. difficile, perhaps from the person's hands or the household environment. (The toilet would be a great source if the dog's a toilet-drinker). The implications of this, for both dogs and people, are unclear. It could be primarily an academic risk (i.e. of little practical significance), or it could be that interspecies transmission of C. difficile plays a role in disease in both species. We simply don't know at this point.

This is also a good example of why educational efforts regarding prudent antibiotic use need to be directed at both animal and human healthcare.

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

Image source: www.sciencedaily.com/releases/2009/05/090507101820.htm

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In yet another tragic example of why large wild species should not be kept as pets, a 37-year-old Pennsylvania woman was killed by her pet black bear. She entered the 350 pound bear's cage, a 15 by 15 foot steel and concrete enclosure (hardly a good environment for a bear) and was mauled. A neighbour then shot and killed the bear. A Bengal tiger and African lion were also present on the property. No indication was given about what might have triggered the attack.

Large carnivorous mammals don't make good pets. It's also questionable whether people can adequately and humanely care for such animals. I have a hard time believing the bear had a good quality of life living in a small steel and concrete pen. The picture above is not from this case but from another bear enclosure elsewhere  in Pennsylvania (see link here).

Every year, there are reports of these types of "pets" severely injuring or killing their owners, yet there is little effort in many regions to control the ownership of these animals. Local officials knew about these animals and the woman had permits for them. Why (and how) someone could actually get a permit to keep these species is beyond me.

Pets are great, but pet ownership has to be logical and safe, and there have to be benefits for both the human and animal. Keeping dangerous animals locked up for curiosity's sake is no longer (or at least should no longer be) socially acceptable. These animals should be in the wild or in a properly managed zoo or wildlife rehabilitation sanctuary.

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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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More from the ASM-ESCMID MRSA in animals meeting…

Dr. Joe Rubin presented some data on antibiotic resistance in Staphylococcus aureus bacteria from dogs and people in Saskatoon, Saskatchewan (Canada). The bacterial isolates came from dogs carrying S. aureus and from dogs infected with MRSA. When you look at the resistance patterns of the S. aureus isolates from the carrier dogs (these are an indicator of what’s around in the general population, and they can cause infections given the right circumstance), resistance was uncommon. Multidrug resistance was present in the methicillin-resistant S. aureus (MRSA) isolates, as expected.

Saskatoon’s an interesting area in terms of resistant bacteria. Various studies from the University of Saskatchewan have reported very low antibiotic resistance rates in bacteria from animals. Certainly, they have some problems like everywhere else, but I find some of their data quite remarkable. They can have a lot more confidence in the use of various first-line antibiotics compared to other regions where resistance is more common and drug options are more limited. I’m not really sure why this is the case.

• Maybe it has to do with the fact that there is less animal movement between Saskatchewan and other regions where there are more resistance problems.
• Maybe the low population density in Saskatchewan plays a role.
• Maybe multidrug resistant bacteria don’t like the frigid Saskatchewan winter (or the fact that there’s no NHL team in the province).
• Maybe they use antibiotics in animals in a much more controlled manner.

Trying to figure out why resistance rates in Saskatchewan tend to be lower would be useful because it might provide some information about how to reduce the risks in other regions.

So, if you’re in Saskatoon and your pet gets an infection, take some consolation in the fact that there’s probably a lower risk that you’re dealing with a resistant bacterium and that your first-line antibiotics will probably work.

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I'm in London (UK) for the ASM-ESCMID conference on methicillin-resistant staphylococci in animals: veterinary and public health consequences. I’ll provide various updates on interesting presentations over the next few days.

Dr. Armando Hoet from the Ohio State University (OSU) presented data on MRSA screening of dogs admitted to the OSU Veterinary Teaching Hospital. They sampled a subset of dogs admitted to the hospital every month over the course of a year.

• 5.7% of the dogs were identified as MRSA carriers. That’s a pretty impressive (and concerning) number. We know that a small percentage of dogs and cats in the general population are positive, but I’ve generally assumed the rate of carriage to be around 1-4%. However, you have to consider the study population whenever you look at numbers like this. Sixty-eight percent of the positive dogs were referral cases, meaning they had had previous contact with the veterinary healthcare system, may have been treated previously with antibiotics and may have had other diseases that increased the risk of MRSA.
• Ownership by people in the human or veterinary healthcare fields were risk factors for infection.  This is not very surprising since such owners would be more likely to pick up MRSA at work and bring it home to infect their pets.

Hopefully the true percentage of dogs in Ohio carrying MRSA is lower than this. Presumably, the rate of MRSA carriage by healthy dogs that are not owned by high-risk people is quite a bit lower. Regardless, it shows that MRSA can be found in a reasonable percentage of animals in the study area (as well as presumably other areas) and that good infection control practices are needed in veterinary hospitals to reduce the risk of transmission.

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

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Here's a reader's question: "Our local water authority here on the East Bay of RI has issued a "boil water" alert because of the presence of e-coli as found in a routine test. My question is:  Do we need to boil dogs' and cats' drinking water as well? Seems that they eat the worst stuff and may have stronger systems?  I gave my dog boiled water at home but then at day care they did not boil the water. "

There’s not a clear answer to this question. Ingestion of bacteria is not necessarily a bad thing. In fact, we ingest huge numbers of bacteria every day. Some dogs (like my dog that eats anything she finds outside) ingest more, and usually no problems develop. Boil water advisories are usually enacted based on detection of E. coli as an indication of fecal contamination. While many (or most) E. coli are harmless, the fact that fecal bacteria are present means that other potentially harmful microorganisms that can be found in feces may also be present. This includes E. coli O157 and Cryptosporidium.

What is the risk for dogs? It’s hard to say. E. coli O157 can cause infection in dogs but this is rare. Dogs that ingest E. coli O157 might shed the bacterium in their stool and potentially infect people. That’s a concern but it’s rare as well. Cryptosporidium is not an important cause of disease in dogs. So, when we look at the highest profile microorganisms in people, the risk to dogs is pretty low. However, we don’t know much about waterborne disease in dogs and it’s certainly possible that other microorganisms could cause disease and that dogs could act as an indirect source of infection of people (i.e. water to dog to person).

So, what should we do during a boil water advisory? I’d probably give my pets boiled water, since I’d be doing it for myself already. It’s not hard to boil a little more water for my pets. Is it really necessary? Who knows? Probably not, but it’s a pretty easy thing to do to reduce any risks that might be present.

It’s never a bad idea to err on the side of caution.

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The investigation into a large E. coli O157 outbreak linked to a UK petting zoo continues, and the number of potentially exposed people is astounding. There are a couple of reasons that I write a fair bit about petting zoos, and they are highlighted here: the potential for exposure of a large number of people and the predominance of children. In this outbreak, it is feared that tens of thousands of people may have been exposed since problems started in August. The exact number of infected people is currently unclear but is in the "dozens," including some with hemolytic uremia, a severe kidney disorder. One report says there are 36 sick people, including 12 children under the age of 10. It's pretty likely that these numbers will increase, and that even more cases will go undiagnosed because they were mild and people didn't get tested. 

This week, testing has been performed on animals and environmental areas on the farm to look at sources of E. coli O157. I'm not sure why this wasn't done a while ago. However, at this point, it's mainly going to be useful to confirm that the E. coli strain infecting people is also present in animals on the farm. Finding or not finding the bacterium at various environmental sites at one point in time really doesn't say much about where it was when people were getting infected. If E. coli was in the animals, it's likely to contaminate various environmental areas. If petting zoo design and hygiene were not optimal, this could result in contamination of visitors' areas.

Some parents have complained that the farm was allowed to remain open for more than two weeks after the first cases of E. coli were reported. That's a very valid concern and one that should be clearly addressed. Once there was reasonable suspicion of the farm being involved, measures should have been taken to reduce further exposure. A good synopsis of these events is available here.  It certainly depicts a less-than-stellar response to a potential outbreak. Although you don't want to over-react and close a facility that was not actually the source, given the potential severity of disease and massive number of people that could be exposed, public health concerns need to supercede economic concerns in situations like this.

Petting zoos will never be "no risk." There is an inherent risk of infectious disease transmission any time you interact with an animal. That being said, there are standard recommendations that are in place to greatly reduce the risk of disease transmission. I don't know much about the quality of infection control practices on this farm, but it's likely they could be better. One writer to timesonline describes how kids are allowed to climb in with the animals and chase after herds of pigs, which certainly suggests a lack of proper control.

People running petting zoos need to take their role in protecting the public seriously. That includes protection from infectious disease and injuries such as bites. Public health authorities need to take a more proactive role. Instead of the standard approach of just providing documents or signs, these events need to be inspected and any problems need to be identified and addressed. The key is to use basic, practical measures that reduce the risk while maintaining the positive aspects of the petting zoo. It's getting better in many areas, but there's clearly still room for improvement.

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The last time I visited the Aberfoyle (Ontario) Fall Fair, the petting zoo was so bad that I ended up writing to the fair organizers and the Wellington-Dufferin-Guelph Public Health Unit. (Neither group replied). It was pretty bad. Young poultry are inappropriate petting zoo animals because of the risk of transmission of bacteria like Salmonella, yet baby chicks were being passed around to young children. One chick was injured by rough handling and the petting zoo supervisor just threw it (still alive) in the garbage. There was a diarrheic calf, poor hand hygiene facilities, and other problems.

We went back to the fair yesterday and I was quite pleasantly surprised: no chicks, no calves, all appropriate and healthy-looking animals, a clean facility and good hand hygiene stations. There were still a couple of suboptimal things, like not having hand sanitizers by one exit, and having a "supervisor" who was staring off into the wilderness and smoking inside the tent filled with kids and straw, but it was night-vs-day compared to the last time. I doubt my letter had much to do with it, but you never know.  I think it's important that people not accept inadequacies that put the public (particularly children) at risk. People need to raise a stink when they see a problem. I wrote earlier today about a child who had her finger bitten off by a petting zoo zebra that had bitten other people. The previous bites may not have been reported because they were minor, but we need to report apparently minor problems so they don't escalate into major injuries, disease outbreaks or other bad scenarios.

Anyway, it was great to see an improvement, and people in the petting zoo appeared to be having a good time. Now if they'd just work on "Big Ned's" food concession, where the only sink seems to be a storage area with no soap or paper towels, and which appeared to be in need of a serious cleaning, or on the little midway, where they were hand cranking the questionable kiddie ferris wheel to get kids off when all the rides stopped working. Baby steps, I guess.

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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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A Montreal man is undergoing rabies post-exposure treatment after being bitten by a bat in Lachine's Summerlea Park. He found the bat lying on the ground and when he picked it up to take a closer look (surprise, surprise) the bat bit him.

This incident shows yet again the need for better rabies education. While we don't want to create fear and loathing of bats, we should consider them rabies-positive until proven otherwise. That doesn't mean we want to eradicate them. It means we want to educate people to enjoy them from a distance and never have direct contact with them.

Never try to touch a bat. A bat lying on the ground in a park is not a healthy bat. It may be sick for various reasons, but rabies is certainly a possibility. If you come across a sick bat, call animal control. They can safely remove it so that no one has the chance of being bitten. If someone has had contact with the animal, the bat must be tested for rabies, as was done here. Rabies is preventable using proper post-exposure treatment, but it's very expensive, a hassle and a series of vaccine's isnt' exactly fun.

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As a vet, I've been bitten by a wide range of animal species. When people talk about animal bites, they usually think about dogs and cats. Horses can (and do) bite as well. Most horse bites are probably playful nips that hurt a little yet don't cause major problems, but some bites can cause serious injuries and infections can result.

A recent paper in the Journal of Agromedicine (Langley and Morris 2009), with the rather unwieldy title of "That Horse Bit Me: Zoonotic Infections of Equines to Consider after Exposure Through the Bite or the Oral/Nasal Secretions". Bites apparently account for 3-4.5% of the approximately 100 000 annual emergency room visits in the US that are associated with horses. The authors of the paper review infections associated with bites and contact with organisms in the mouth and nose of horses.

A large number of bacteria have been associated with horse bite infections in people, including Actinobacillus, Streptococcus, Psuedomonas and Staphylococcus species. Some viruses can theoretically be transmitted by bites, but there's little evidence that this actually happens.

Although viruses are not of as much of a concern overall, rabies needs to be considered in every bite from a mammal. We pay a lot of attention to rabies with dogs, cats and wildlife, but it often gets ignored with horses. While I'm not aware of any reports of rabies transmission from horses to humans by a bite, it could happen.  Fortunately, rabies is rare in horses so the likelihood of exposure from this species is very low. However signs of rabies aren't always obvious initially, and rabies in horses may mimic other diseases. Sometimes, rabies looks like colic, and human exposure through bites or other contact is possible when handling, evaluating and treating affected horses.

Unlike with dogs and cats, there are no clearly defined protocols for dealing with bites from horses. Any dog or cat that bites a person is supposed to be quarantined for 10 days. The reason for this is if the animal is rabid and the disease is advanced enough for the animal to be capable of spreading rabies virus, it would invariably develop signs of rabies and die within this time period. We don't have similar guidelines for horses. I suspect the 10 day observation period would be adequate but we don't have good data. The paper states that in Kentucky, a 14 day observation period has been used by the state Department of Public Health.

At the conclusion of the paper, the authors make a few important general recommendations for reducing the risk of disease transmission from bites and oral or nasal secretions of horses:

• Use good general hygiene, especially hand hygiene, after any contact with horses.
• Use gloves and gown or lab coat when examining horses in a veterinary clinic or hospital. (This might be overkill for all horses. We don't require gloves for every horse contact, just contact with mucous membranes (e.g. mouth, nose), wounds, incision sites and other high-risk areas. I think bare hands are fine for general contact as long as there is good attention to handwashing after.)
• Consider mask and goggles if the horse is coughing or sneezing.
• Develop standard operating procedures for handling sick horses.
• Use isolation when needed.

I'd add a few more points:

• Avoid bites. Pay attention to what you are doing around horses to reduce the risk of being bitten. Do not encourage playful behaviours (e.g. nipping) that could lead to bites.
• If you are bitten and it breaks the skin, clean the site thoroughly with soap and water. If there is significant trauma, or if the bite is over a joint, hand, foot, or a prosthetic device, you should see a doctor immediately because antibiotics are most likely indicated. If you have a weakened immune system, you should be evaluated by a doctor after any bite.
• Avoid contact with the horse's mouth or nose if you have skin lesions. Cuts and scrapes can allow bacteria to enter your body and cause infections. If you have a cut on your hand, make sure it is covered with a glove or waterproof dressing if you are going to have contact with the horse's mouth or something that came from its mouth (e.g. a bit).

This Worms & Germs blog entry was originally posted on equIDblog on 02-Sep-09.

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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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Methicillin-resistant Staphylococcus aureus (MRSA) infections are an emerging problem in dogs and cats. They're a huge problem in human medicine, and the emergence of MRSA in pets can be directly traced to the spread of MRSA in people.

A big problem with MRSA infections is that they can be difficult to treat because they can be resistant to many antibiotics (not just methicillin). This complicates treatment, but it's important to remember that most MRSA infections are treatable.

An important concern with MRSA is that it may lead to unnecessary veterinary use of drugs that are critically important for treatment of life-threatening infection in humans. Vancomycin is an antibiotic that is occasionally used to treat MRSA infections in dogs, although I've never had to use it. I stumbled across a supposed "veterinary information website" today that stated vancomycin is the main treatment for MRSA in dogs. It quickly became clear the authors had no clue about the topic, because they kept calling MRSA a virus (always scrutinize the source of information, especially on the internet). Information like this doesn't help with prudent use of drugs like vancomycin.  It's important for pet owners and veterinarians alike to realize that these "big-gun" antibiotics (such as vancomycin) are rarely needed for MRSA infections in dogs and cats. There are almost always other, and usually better, options.

Vancomycin is also sometimes inappropriately used in animals, which can lead to worsening of infection.  For example, if vancomycin is mistakenly given orally, the drug is not absorbed from the intestinal tract and therefore has no chance of fighting infection elsewhere on the body.

In general, MRSA infections are quite treatable. Survival rates tend to be high and, with proper treatment, should be no lower for MRSA infections versus infections caused by susceptible strains of S. aureus. A comparison of MRSA versus susceptible S. aureus infections presented last year reported no difference in survival rates, with an overall survival rate of >80%. The key is diagnosing the infection early and getting started on the right treatment. That means getting cultures done earlier, rather than later.

While increasing antibiotic resistance may lead to more need for "big-gun" antibiotics in some cases, we need to act prudently and restrict their use to situations in which they are absolutely required. Use in animals needs to be very prudent to avoid contributing to antibiotic resistance in people. Inappropriate use in animals could lead to more calls to restrict veterinary access to various drugs, which could threaten treatment of other animals with other types of infections.

Don't confuse "big-gun" antibiotics with the best treatment.

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

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I received the following question the other day: "I have a friend who had chemo embolization on tumor on liver in late June. She is in hospital now, and an abscess was discovered on liver.  Pathology results said "equine strep".  Her brother visited immediately after procedure, and he works with horse full time."

Streptococcus is a group of bacteria that includes many different species. There are two main species in horses Streptococcus equi subsp. equi (aka S. equi, the cause of strangles) and Streptococcus equi subsp. zooepidemicus (aka S. zooepidemicus, a cause of various types of infections). As you can guess by the 'equi' name, their natural host is the horse. Strep infections are very common in people, but rarely involve these two species. Nonetheless, infections with either Streptococcus equi or S. zooepidemicus can be found in people, but S. zooepidemicus is most common. Usually, these infections develop in people who are already sick for another reason, have compromised immune systems, or in young children. Interestingly, not everyone that is infected reports direct or even indirect contact with horses.

Back to the question: it's hard to say what's going on here based on the the general term "equine strep", but presumably the person has an infection with S. equi or S. zooepidemicus. Whether horses are actually involved will be tough (or impossible) to determine. It's a tempting hypothesis that the patient's brother carried the bacterium from the farm to the hospital, but I'd be wary about making a definitive statement about the bacterium's origin solely based on that. There are ways to investigate this further, such as trying to isolate Streptococcus species from horses on the farm, typing them and comparing them to the strain that caused disease in the person, but this type of testing is very costly and almost never performed, as human infection with these species is so uncommon.

This should be a good reminder that people who are sick and in hospital are at higher risk for developing infections, and they can get infections from bacteria that rarely cause disease in healthy individuals. While there is no proof of a link to horses (at least in this case), good infection control practices should be used whenever anyone visits someone in the hospital. That would include not wearing barn clothes to the hospital and paying close attention to handwashing.

This Worms & Germs blog entry was originally posted on equIDblog on 26-Aug-09.

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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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People are justifiably concerned about overuse of antibiotics, in both veterinary and human medicine. There's ample talk about restrictions on use of antibiotics in animals (especially livestock), which is an area that needs good, objective research and discussion. Some politicians have made grand statements about restricting antibiotic use and have proposed strict legislation. (In North America, there's a lot more talk than action). However, I continue to be amazed that amongst all the hand-wringing about antibiotic use in animals, governments haven't taken the very simple initial step of making all antibiotics only available by a veterinarian's prescription. This seems to be a very logical first step, but it's one that almost never gets discussed.

A good example of why this type of regulation is needed comes from a website about Terriers, which says:

"Almost all human antibiotics can be used on dogs and almost everyone either has old antibiotics in their medicine cabinet or knows people that do. Look around, and you will probably find what you need."

• What??!! Just what we need... recommendations that people sift through old drug supplies for a dose or two of who-knows-what, which may or may not be expired and may or may not be potentially useful for whatever problem is present, and may even be harmful. Determining whether or not an antibiotic should be used, and determining the drug and dose is not something that should be up to a pet owner. It should be up to a veterinarian.

"Drugs past the expiration date are going to be fine as long as they are no older than a year or so past the expiration date (even then they may be fine)."

• Dumb. Drugs don't instantly go bad at their expiration date, but you don't know what you have left at that point. If you actually need an antibiotic, you need one that works like it's supposed to.

"If you prefer to order your medications outright, you can order cephelaxin (Fish-Flex) from most dog catalogues and it will cure 99% of your flesh wounds as well as most urinary tract and ear infections. Cephalexin or cefalexin is sold as a fish antibiotic in dog catalogues with full-knowledge it is being used for off-label treatment in dogs. It should cost about $30 for 100 250 mg. capsules, which is a perfect dose for a terrier."

• Ugh!!  A good example of why loopholes like easy access to antibiotics for fish use need to be closed. Many dog internet sites sell fish drugs. I wonder what percentage of "fish" drugs actually make it into fish?

"You probably have some old amoxicillin around the house from the last time you got sick. This is fine to use even if "expired" more than a year ago. Expiration dates on non-liquid antibiotics are a marketing tool (i.e. they encourage people to throw good drugs down the drain) and have no scientific basis -- a fact demonstrated by the U.S. military."

• Can't say I've seen that study. Expiry dates aren't a marketing ploy. You should use all the antibiotics prescribed, and if for some reason you have any left, you should throw the rest out. It has to do with health and proper use of antibiotics, not marketing.

Take home messages:

• It's time for politicians to actually do something about antibiotic use and ban all over-the-counter access.
• Beware of internet advice. Scrutinize sources of information carefully.

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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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Clallam County (Washington) is considering dropping the requirement that pets be vaccinated against rabies in order to get a license. It's pretty clear that this is only based on a desire to get more people to pay for licenses. Sheriff Bill Benedict is quoted as saying "My view on this is, we're leaving money on the table by not finding a way to get more people buying licenses."

This money-driven mindset makes no sense, and raises the question "what is the purpose of licensing pet?" Is it only to provide a source of government income (in other words, a tax on pet ownership), or is it for greater purposes such as helping protect the pet and human population?

Another quote from Benedict: "You would still be required to have your pet vaccinated, but that would be more of an issue between the pet owner and the veterinarian." This isn't an issue solely between the pet owner and the veterinarian. Rabies vaccination is still required by law. Veterinarians do not have a mandate or power to require vaccination and enforce the law. With this "You still need have your pet vaccinated (wink, wink, nod, nod)" approach, the municipal government is essentially saying, "We really just want you to pay us for a license. We don't really care whether your pet is vaccinated against rabies or not as long as you give us money."

A local veterinarian wrote to the commission that "Licensing pets is sometimes the only reason an owner will get rabies vaccines... Rabies vaccinance is the law of the state, the law of the county. Licensing, in my view, is less important than vaccinating for rabies and may facilitate even more rabies cases."

Well said. The county may get more money because more people will get licenses, but it's certainly possible that fewer pets will get vaccinated. Just one rabies exposure could negate the increased revenue from more licenses based on the high costs of rabies post-exposure treatment (let alone the risk of disease, stress of exposure, costs required for investigating cases...). Since all those costs would come from other peoples' budgets, however, I doubt they're too concerned.

Benedict also stated "Most pet owners -- in fact the vast majority -- if they're responsible enough to get a license, they're responsible enough to get a pet vaccinated."

Good thing he's not a lawyer. It seems to me that he just shot his argument down. If the majority of pet owners that are responsible enough to get a license are also responsible enough to get a pet vaccinated, then why is this change required?  An attempt to increase cashflow is not a good reason to change rules that are designed to protect the public and pets from a fatal disease.

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A horse in Harford county Maryland has been euthanized because of rabies. The horse first starting showing signs of disease in mid-July, which manifested as "striking changes in behaviour." The report doesn't say when the horse died, but animals typically die within a few days of the onset of neurological disease. The horse was transferred to the New Bolton Center where rabies was diagnosed. Subsequent testing showed it was a raccoon rabies strain, although that does not mean that a raccoon was the actual source of infection.

Public health officials implemented a 45 day quarantine of the farm. Stray cats (about 25) were caught and euthanized. Fortunately, the family pets were properly vaccinated and have received booster shots (plus presumably a period of observation at home... a much better situation than if they were not vaccinated).

People that had contact with the horse have received rabies post-exposure treatment. This includes one person who had to be tracked down overseas.

Harford County Health Department spokesperson Bill Wiseman said "There was never a risk to public safety. This incident was a great example of public health work in action and cooperation between local, state and in this case, international authorities." I don't buy the statement that there was no risk to public health. While the risk of rabies transmission from infected horses is very low, it's not zero. Rabid horses have killed people because of their abnormal and sometimes aggressive behaviour. Further, the fact that this horse had rabies means that it got it from something. Rabies can have a long incubation period so it's not guaranteed that it acquired it on the farm, but you have to be prudent and assume that there is infected wildlife in the area that could pose a risk for other animals or people. Public health authorities managed the situation well and reduced the public health risks, but there were certainly still risks.

Rabies vaccination is highly effective. There is no statement about whether this horse was adequately vaccinated but it's unlikely. Proper vaccination would likely have prevented this horse's death, as well as the death of the stray animals, cost of vaccination of people, cost of veterinary care for this horse, quarantine of the farm and the associated financial and emotional costs. A dose of vaccine that costs a few dollars could have saved thousands of dollars and emotional stress.

Rabies is a rare disease in horses but its severity means it should not be ingored. Vaccinate your horses.

This Worms & Germs blog entry was originally posted on equIDblog on 14-Aug-09.

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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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A 74-year-old Colorado woman that had been warned repeatedly not to feed bears was killed by one. The circumstances surrounding the attack are not known, but there was clear evidence of mauling. Wildlife officers had received numerous complaints for at least a decade that the woman was habitually feeding bears.  She was warned several times but never ticketed because of difficulty gathering solid evidence of the illegal activity. Wildlife officers and sheriff's deputies killed two bears after the attack. It was reported that a necropsy of the larger 394 lbs animal showed that it appeared to have been feeding on a human, but this has not been officially confirmed yet.

As we've discussed before, people often feed wildlife thinking they are helping the animals, but the opposite is true. Numerous problems are caused by feeding wildlife, including making animals dependent on people for survival, decreasing animals' fear of humans, encouraging animal encroachment into urban areas and generally increasing the chance for both human and animal injury and infection.

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State public health officials are trying to get the word out about a potential rabies exposure in Annapolis, Maryland.  A rabid kitten was discovered outside a Sears store at the Westfield Annapolis shopper center. The concern is that people may have handled the kitten and been exposed. It's a major concern with kittens because they can be hard to resist - a pathetic-looking/cute little kitten sitting around in a public place could easily be picked up by many people. Also, when rabies is found in a young kitten, there are often other rabid kittens from the same litter in the area. Rabid stray kittens have caused widespread exposure in the past, and this case may be no different.

Anyone who recently had contact with a stray kitten in the area in question should contact public health officials as soon as possible. Simply touching the kitten is not a rabies exposure risk, but anyone that has had any contact with a potentially rabid animal should talk to public health officials to determine whether there is any risk of infection and whether post-exposure treatment is required.

While kittens are hard to resist, avoid handling stray kittens. This is especially true if it's transient handling where you will never know what happened to the kitten afterwards (as opposed to someone adopting a kitten off the street - this is still risky from some standpoints, but at least you know if the kitten gets sick and you can make sure that it is tested for rabies or other other zoontic diseses, if need be).

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It seems like whenever a hit TV show or movie features an animal, there's concern about the "101 Dalmatians effect," whereby there's a mad rush to get the animal for a pet. When 101 Dalmatians was a hit movie, there was a huge spike in sales of this rather unusual breed - a breed which is certainly not for everyone. This results in unqualified breeders and puppy mills churning out marginal or poor quality pets and people getting a pet that really doesn't suit them. The end result can be a lot of disappointment, heartache and abandoned pets. This pattern has been repeated with various other breeds and animal species, and there is concern that the same will happen with guinea pigs as a result of the new Disney movie G-Force.

In terms of human health, guinea pigs are relatively benign. Bites and scratches are probably the biggest concern, and are often the result of improper handling. Bites can become infected from bacteria in the guinea pig's mouth or from bacteria on the person's skin. Allergies are also a potential problem. The number of diseases that are known to be transmitted by them is relatively small, and the risk of disease transmission is rather low.

Lymphocytic choriomeningitis virus (LCMV) is a concern with all rodents. It typically only causes disease in people with compromised immune systems, but can result in fatal infection. The risk of a guinea pig carrying this virus is likely greatest in animals from large rodent breeding facilties and when there is contact with wild rodents.

Ringworm is perhaps the most common infection that people get from guinea pigs (apart from infections following bites). Even healthy guinea pigs can carry the fungus that causes this disease.

Guinea pigs can carry Salmonella, but they are quite susceptible to infection and usually get quite sick. The risk of a healthy guinea pig shedding Salmonella, especially for a prolonged period, is pretty low. The risk is presumably greatest shortly after purchase.

Rabies is always a potential problem in mammals but the risk is very low with small rodents such as guinea pigs. (Very low isn't zero though, since hamsters have been sources of potential rabies exposure).

There are other potential problems too, but they are all quite rare.

The keys to reducing the risk of infection are:

• Purchase a guinea pig that looks healthy, is eating well, has no skin lesions or diarrhea, and is active and alert. Ideally, purchase an animal from a local breeder as opposed to a store that might have obtained the animal from a large breeder, via an animal warehouse, hundreds or thousands of miles away.
• Learn how to properly handle a guinea pig to reduce the risk of bites and scratches, as well as injury to the animal.
• Keep pet guinea pigs away from wild rodents.
• Use good general hygiene. Wash your hands after handling the guinea pig and after contact with bedding.
• Thoroughly wash any bites or scratches.
• Take particular care in the period shortly after purchase.
• Even though the cost of the guinea pig is less than the cost of a vet visit, a veterinary examination is important when the animal is sick. Apart from our ethical responsibility to take care of our pets, it's important to make sure that illness isn't caused by a disease that can be transmitted to people.

More information about the diseases mentioned above is available on the Worms & Germs Resources page. While we don't have a specific guinea pig info sheet yet, much of the information on the hamster information sheet also applies to guinea pigs.

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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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I received a flyer from Zoologix, a company that offers various (typically unvalidated and unproven) PCR tests for animals. The flyer headline was "Pets can carry MRSA - but testing can help."

Testing in certain situations is useful, but this is almost always limited to diagnosis of animals with active infections (i.e. they're sick). PCR is not a good way to make such a diagnosis, because the test doesn't tell you anything about the bacterium's susceptibility to other antibiotics. Screening of pets just to determine whether or not they carry MRSA is rarely needed, and currently there is no evidence that PCR is a reasonable test for this.

There are no validated PCR tests for MRSA in animals. We looked at using a human test in horses and it failed miserably. There are validated tests for use in people, and they are quite good: they accurately identify MRSA and differentiate it from other methicillin-resistant staphylococci and from methicillin-susceptible S. aureus. That's critical, because you have to know what a positive test really means.

I called the company and asked what the test actually detects. They said it detects the mecA gene, the gene that confers methicillin-resistance to staphylococci such as S. aureus. However, this gene can be present in other staphylococci that can be found in many  healthy dogs and cats (10-30% in some studies). It does not actually detect MRSA and a large percentage of samples that give positive results will be false positives. The tests that are used in humans are specifically designed to look at two things in combination: whether S. aureus is present and whether it has the mecA gene (methicillin-resistance). This is the right approach because it excludes all those other false positives. Detecting mecA alone is completely useless. It's interesting that the flyer states "PCR testing is fast, effective and accurately differentiates MRSA from other bacteria - even other Staph strains." Based on what the company told me over the phone, with regard to the test they're advertising, that's a blatant lie.

This is an example of a combination of bad science and bad ethics. This company has no business marketing this test. It's false advertising, because the test isn't an MRSA test. Their justification for using it is similarly weak. Anyone thinking about using this test should run away quickly! The issues with this test (and others) should also be considered when deciding whether to use this company for any tests.

More (and accurate) information about MRSA can be found on the Worms & Germs Resources page.

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A recent case report in the Journal of Clinical Microbiology (Cooke et al. 2009) described isolation of Salmonella Apapa from the feces of a 67-year-old woman with abdominal pain. The patient had a history of various medical disorders but no clear evidence of a compromised immune system. She was hospitalized, and Salmonella Apapa was identified from a stool sample collected the day after admission. Fortunately, her abdominal disease resolved (whether it was caused by Salmonella or whether Salmonella was an incidental finding can't be stated definitively), and she was ultimately discharged from the hospital.

Salmonella diagnoses usually lead quickly to questions about food and reptiles.  In this case, the woman's son had recently moved in with her, along with his two bearded dragons. The lizards were kept in a tank, and the woman reported having no direct contact with them. Samples from the lizards' feces and the tank environment were collected, and the same Salmonella strain was isolated. While getting Salmonella from a reptile is certainly nothing new, this case report highlights some important points.

• The person that was infected did not report any contact with the reptiles or their tank. Therefore, some type of indirect exposure must have occurred. This is why reptiles should not be kept in high-risk households even if the high-risk people don't have direct contact with them. High-risk households include households with young children (less than 5 years of age), elderly individuals, pregnant women and immunocompromised individuals.
• It's not just high-risk people that get sick. This person was perhaps on the crux of being considered high-risk based on her age and previous medical problems, but she was certainly not a clear example of the people we assume are at higher risk. A huge number of reptile-asociated cases of salmonellosis are reported every year. While high-risk people are more likely to get sick (and more likely to develop severe illness), healthy individuals can be infected as well.

Reptiles can make good pets. I used to have a pair of Red-Footed tortoises, so I'm certainly not anti-reptile (despite what the emails I typically get after posts like this say). People who have or who are comtemplating getting a reptile for a pet need to be aware of the associated risks, as they are certainly real and should be taken seriously.

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A stray cat taken by someone to a family gathering in Delaware, USA, resulted in 17 people from 4 states undergoing rabies post-exposure treatment. The kitten was found by the side of the road, taken to the gathering (it's unclear whether it was found on the way there or earlier), and when it became ill after the gathering, it was diagnosed with rabies. This is just one example of the potential for widespread exposure of people handling stray (or recently stray) animals at events like reunions, flea markets and sports tournaments. Because these animals (especially cute little ones like kittens) often get handled by a lot of people, a lot of people can be exposed to rabies if the animals are carrying the virus. These situations create major problems for public health personnel, because it's difficult to identify all the individuals who were potentially exposed when they are dispersed across the country.

While generally uncommon, this type of scenario happens a few times a year.

• Don't bring stray, or recently adopted, animals to public events.
• Ensure that your animals are properly vaccinated against rabies. Animals that have not been properly vaccinated should not be taken to public events.
• Don't handle stray animals.
• If an animal that you have recently adopted gets sick, make sure rabies is considered and, if necessary, make sure the animal gets tested.

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A paper in the July 1 edition of the Journal of the American Veterinary Medical Association (Muller et al) describes a case of encephalitis (brain inflammation) in a rabbit caused by human herpesvirus type 1.  The owner had a severe herpes infection with genital and oral lesions five days before the rabbit got sick, and reported "intensive" nose-to-nose and mouth-to-nose contact with the rabbit. The rabbit started off with a decreased appetite and excessive tear production (epiphora) in one eye. Then other signs of eye and neurological disease developed. Despite aggressive treatment, the rabbit deteriorated and was euthanized after a week of hospitalization. Subsequent testing identified human herpesvirus type 1 in the rabbit's brain.

Human herpesvirus type 1, also called herpes simplex viruses type 1 (HSV-1), is a common sexually transmitted disease (STD) in people. It can cause oral, genital and ocular (eye) lesions. Humans are the primary host of this virus, but it has been found in species such as rabbits, rats, mice and chinchillas. In rabbits, it usually causes encephalitis, and is almost always fatal for these animals.

This case shows how viruses typically associated with one species can sometimes affect others. While we usually focus on microorganisms moving from animals to humans, they can also move in the opposite direction, as was presumably the case here. Close face-to-face contact with the infected owner was probably the source of the virus. This is an example of an uncommon event, but one that should not be ignored.

If you have an active herpesvirus infection:

• Limit close contact with rabbits (and, to be on the safe side, probably restrict contact with other pets as well). In particular, avoid contact with the mouth, nose or eyes.
• Wash your hands or use an alcohol hand sanitizer regularly, particularly after using the washroom or having any contact with infected sites/sores.
• Make sure herpesvirus infection is considered if your rabbit develops eye or neurological disease.

The risk of rabbits transmitting human herpesvirus is completely unclear. Common sense dictates that anyone hanlding a potentially infected rabbit should restrict contact with the eyes/mouth/nose, wear gloves, wash hands after contact (even if gloves were worn) and avoid contamination of clothing.

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In an interview with the San Francisco Chronicle, veterinary dermatologist Dr. George Doering makes a pretty obvious but very important comment that is worth repeating:

"The biggest problem we have in almost all the fields of veterinary medicine is compliance. You say to a client, "This dog needs to take this antibiotic twice a day." Well, the reality is we might be lucky if they get it once a day. ...They don't want to accept the seriousness of the problem."

This very true and very important. Compliance with recommended antibiotic therapy is probably a major factor in treatment failure, recurrent infection and antibiotic resistance. Antibiotic dosing regimens are specifically designed to ensure that the right concentration of drug is present in the body for the appropriate time. Missing doses, skipping days, not making sure the animal actually ingests the drug, and other problems that result in the pet not getting what is was supposed to get are very important.

It's easy to understand why this happens, because administering antibiotics (particularly to some difficult-to-pill dogs and cats who can smell the medication when it comes in the house!) can be a hassle. Because of this (and the very natural human tendency to take the easy way out), it's really important for people to understand the concerns about inadequate antibiotic administration and what they need to do.

• Follow the entire treatment course. You should have no antibiotic left at the end of the recommended treatment time.
• Make sure your pet actually swallows the antibiotic. If you add pills to food, make sure you check to see that the pill isn't left behind. It's amazing how animals can eat a big bowl of food and leave behind a little pill. The picture shows how my dog Meg can, in the process of inhaling her food at an incredible rate, leave behind a tiny ephedrine pill.
• If your pet will not eat the drug voluntarily, talk to your vet about other ways to administer it, such as compounded in chewable treats. Depending on you and your pet, opening your pet's mouth and placing the pill at the back of the tongue may be an option. Talk to your vet about this first and make sure you wash your hands after. If you think there is a risk you might be bitten, if you are at high-risk for infection because you are immunocompromised, elderly or pregnant, don't try to "pill" an animal in this manner.
• If you still can't get the drug into your pet, talk to your vet right away.  If you wait a couple of days or a week or more to tell your vet, your pet may be even sicker by then. There may be other options to oral drugs such as injectable antibiotics. This might end up being more expensive or difficult (e.g. you may have to take your pet to the vet every day for its medication), but it will be better for your pet and may even save you money in the long run by ensuring the infection is properly and completely treated the first time.
• Never stop treatment because your pet looks better. Often, signs of infection get better before the bacterium is completely eliminated. Stopping too soon allows the bacterium to regrow, potentially as a more resistant form.
• If you are supposed to take your pet to the vet for a recheck at the end of treatment, then do so. Sometimes longer courses of antibiotics may be needed, and it's much better to continue the current treatment course than to have to start again a couple weeks down the road when the infection has returned (sometimes with a vengeance).
• If in doubt about anything, call your veterinarian.  He or she is there to help, and wants your pet to get the best treatment possible.

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Tularemia has been diagnosed in five dogs and cats in Sioux Falls, South Dakota. At least one of the pets has died. Tularemia, sometimes referred to as "rabbit fever" is caused by the bacterium Francisella tularensis. Infections occur throughout much of the Northern Hemisphere but are much more common in certain regions, such as the central US. This bacterium has received a lot more attention over the past decade because of its potential use as a bioterrorism agent, but infections have been occurring in people and pets for a long time. In North America, the cottontail rabbit, wild hares and some rodents are the main reservoirs. People and other animals get infected through close contact with infected animals (e.g. rabbit hunting) or through bites from blood-feeding insects. 

There was no mention of human cases in the recent report from South Dakota. One of the implications of identifying this disease in pets is that whatever infected the pet could also be a risk for people. If the pets were infected by contact with wild animals, people with similar contact with wild animals could also be exposed. If there is no chance the animals had contact with infected wildlife, then insect-transmission is most likely, and the same could happen to human members of the household (or elsewhere in the area). Therefore, diagnosis of tularemia in a person or pet should put both veterinarians and physicians on the lookout for further cases in all species.

Transmission of tularemia from infected pets to humans is also a concern. This has been reported in numerous instances, most often with cats. There are published reports of transmission from dogs to humans, but these are less convincing than the numerous cat-to-human reports. There's also a report of tularemia transmission from a hamster to a child. The overall risk of transmission is probably low, but tularemia can be spread from pets to people by scratches, bites, and perhaps regular close contact.

You can reduce the risk of your pet being exposed to tularemia by:

• Keeping pets indoors as much as possible. Cats should stay indoors. Dogs should not have uncontrolled outdoor access.
• Dogs should not be allowed to hunt rabbits in areas where tularemia is endemic.
• Animals that venture outside should be checked regularly for ticks and a preventive medicine program for ticks should be in place.
• Routine measures to reduce bites and scratches from dogs and cats should be taken.

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Here's a question I received the other day:

"Do people who work with animals and who work in barns need a tetanus shot as a result of this type of work?  We have Therapeutic Riding Programs in the region and there is a sense that perhaps the volunteers and those who frequently tend the horses need to receive this.  Is this the case?"

Tetanus is a disease that we are quite concerned about in horses because horses are very susceptible to it. That's why we vaccinate them yearly. Tetanus can also affect people, but very rarely because of vaccination and because people have lower susceptibility to the disease. While we pay a lot of attention to tetanus in horses, this does not mean that being around horses increases a person's likelihood of exposure to tetanus. The bacterium that causes tetanus, Clostridium tetani, lives in soil and commonly present in the environment. The more environmental exposure that you have (especially to soil), the greater your risk of exposure to C. tetani. Being around horses doesn't increase your risk any more than doing other things outside.

Whether you have contact with horses or not should not change your approach towards tetanus prevention. You should be vaccinated against tetanus every 10 years. Many (probably most, actually) adults are not up-to-date on tetanus vaccination. Adults tend not to get booster shots on schedule, and often only receive them when they have had a wound that requires medical care. For example, If you get stitches, the medical staff will almost certainly inquire about your last tetanus shot, and give you another one if you haven't been vaccinated in the past 10 years (or if you can't remember).

More information about tetanus in horses is available on the equIDblog Resources page.

This Worms & Germs blog entry was originally posted on our sister site, equIDblog, on 10-Jul-09.

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My dog, like most labs, loves to swim (actually, she's incredibly lazy and prefers to wallow in the water, not actually exert herself). Many dogs like her often go into swimming pools in the summer, which leads to the question "Is this an infectious disease risk?"

The honest answer is we don't really know. The reasonable answer is the risks are pretty low, especially when a little common sense is exercised. You are probably more likely to get a pool-associated infection from another person than a dog, although the risks are not zero.  A dog is probably less likely to defecate in the pool than an infant or toddler!

Various infectious diseases such as cryptosporidiosis, norovirus infection and E. coli O157 have been linked to swimming pools - all associated with transmission from people. As with most infections, the very young, elderly, immunocompromised and pregnant women are at higher risk.

Like many things in life, there is some degree of risk associated with letting the pooch go for a dip in the pool, but you have to consider the risks and benefits together. The overall risk of infection from swimming with a pet in a well-maintained pool is quite low. The risks is probably even lower in a household pool (where dogs would have access) compared to a heavily-used public pool. Good general practices can reduce the risks further. Chlorine can kill most (but not all) possible causes of infectious diarrhea, but it doesn't work instantly. If someone or something contaminates the pool, there is a window of opportunity, that may last minutes to hours, for transmission of infection. However, some pathogens can survive for days in a pool, if not more. Therefore, chlorination is useful but not fool-proof.

• Keep dogs that have vomiting, diarrhea or skin infections out of the pool. Dogs that have had diarrhea should probably be kept out of the pool for a couple weeks.
• Don't allow dogs known to be shedding infectious agents like Salmonella and Giardia in the pool. Some healthy dogs shed these organisms and it's certain that infected dogs go into pools with no problems, but if you know that a dog is shedding an infectious agent it shouldn't be in a pool.
• Don't allow dogs that have fecal staining of their haircoat in the pool.
• The same rules should apply to people. People with diarrhea should stay out of the pool since they are probably a greater risk for transmitting disease. It has been recommended that people not use a pool if they've had diarrhea in the past week.

The CDC has a good site about recreational water illnesses, which can be accessed by clicking here.

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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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Tuberculosis (TB) is an incredibly important disease caused by Mycobacterium tuberculosis. It's a huge problem internationally, and the problem is getting worse in many areas. Another cause of "tubercular" (or tuberculosis-like) disease is Mycobacterium bovis, a related microorganism whose main natural reservoir is cattle.

Mycobacterium bovis is cause of bovine TB. It can also infect people (usually through drinking or eating unpasteurized dairy products) and pets. Pets can be exposed by a few different routes, including eating contaminated dairy products, eating infected animals (e.g. snacking on carcasses of wildlife like deer that have died of the disease), and perhaps from direct exposure to wildlife carrying the organism. Mycobacterium bovis is an important problem in some areas, typically because of its presence in a wildlife reservoir like deer or the European badger (a major problem in the UK).

Mycobacterium bovis can cause serious disease in pets. It often causes non-specific signs that makes it hard to diagnose until disease is very advanced (and unfortunately likely beyond the point of successful treatment). Some groups recommend prompt euthanasia of infected pets without considering treatment because of the potential for infection of people. The risk of pet-human transmission is completely unclear, but it's such an important disease that some people think any risk is unnecessary and unjustifiable. So, the key is avoiding infection in the first place (for both people and pets). This is of particular concern in regions where M. bovis is present in wildlife and cattle. In areas where it is not known to be present, there should be little to worry about.

Here are some simple steps that can help you reduce the risk of your pet becoming exposed to M. bovis:

• Keep cats indoors.
• Don't allow dogs to roam free outdoors.
• Don't allow animals to have access to unpasteurized dairy products or dead animals.

Pretty basic, isn't it?

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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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There is apparently a thriving black market for baby red-eared slider turtles in Baltimore. The sale  (and possession) of small turtles is illegal in Maryland, like many other regions, largely because of public health concerns regarding Salmonella.

Over 100 hatchling turtles have been seized in the past 2 weeks. Baby turtles offer a good profit margin for black market vendors. They can be purchased from farms in the southern US for about $1 each and then resold for many times that amount. One person was caught selling turtles out of the back of a van. (Why anyone would buy anything from someone selling out of the back of a van is beyond me!)

People buy turtles thinking they make cute pets, not realizing what they need to do to keep them healthy as they grow. Turtles that are fortunate enough to be raised properly create another problem, since most people are not willing or able to take care of adult turtles that reach 10-12 inches in length. This can result in turtles being killed or abandoned.

Another major problem in the risk of Salmonella. Turtles very commonly carry this potentially harmful bacterium, and they are an important source of infection in people. The concerns are greatest with young children who may handle small turtles and put them in their mouths. People need to think before they buy. Before getting any pet, learn about the animal, including requirements for care and human health risks (and also if it's legal). A little common sense goes a long way.

More information about Salmonella and turtles can be found on the Worms & Germs Resources page.

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I recently wrote about a Dutch study of zoonotic parasites in pet feces and pets' haircoats. As part of that study, they asked pet owners about certain behaviours in their pets, and got some interesting answers.

60% of pets visit the bedroom (I'm surprised that's not higher), with 45% of dogs and 62% of cats allowed on the bed, and 18% of dogs and 30% of cats allowed to sleep in the bed with the owner.  While the UK's Chief Vet has warned against allowing pets into bedrooms and allowing them to sleep in people's beds, I don't have the same concerns - as long as common sense prevails.

45% of cats are "allowed" to jump on the kitchen sink. I don't know if they truly mean allowed, or whether the cats simply do this. I certainly don't "allow" my cat to be on the kitchen counter, but it's certain possible he is when I'm not looking. There are some potential concerns about pets hanging around food handling areas, so it's best to actively discourage this behaviour.

55% of owners clean their litterbox more often than twice a week. While daily cleaning is important for high risk people and high risk households, and is ideal for everyone, less frequent cleaning like this is acceptable for most people as long as it's done properly (See our Resources page for details about litterboxes).

15% of dog owners and 8% of cat owners reported always washing their hands after contact with their animals. This is surprisingly high - I wonder if it's really true, or whether some of those do it regularly but not always, or some think they should do it but don't really. Certainly, regular handwashing is important and it's ideal to do it after every animal contact, but that's admittedly hard to do in a household. I try to have good hand hygiene practices but I certainly don't always wash my hands everytime I should. Handwashing after every animal contact is more important for high risk people such as people with weakened immune systems.

39% of dog owners never clean up their dogs' feces. WHAT??!!  That's surprisingly high. When you consider how densely populated the Netherlands is, and that there are around 1.8 million dogs in the country, that's a lot of dog poop. That could be one reason why they found that dogs that were allowed off the leash outside were much more likely to have Toxocara eggs on their coat.

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Giardia is a protozoal parasite that can cause diarrhea in multiple animal species. This microscopic parasite is a zoonotic pathogen that can be transmitted between animals and humans, and there are conerns about the role of pets in human disease.  Various studies have evaluated the presence of Giardia in healthy dogs and, to a lesser degree, cats. Typically these studies report that  about 7% of healthy dogs are shedding Giardia in their stool, but all Giardia are not the same in terms of the risk of transmission from dogs to humans. There are various types of Giardia, and some only infect specific animal species and not people. In dogs, assemblages (types) C and D are most commonly reported. These are considered canine-specific types and are therefore not a concern for transmission to humans. Assemblage A is an important zoonotic type which can infect dogs and humans, and this type can certainly be found in healthy dogs, but it seems to be relatively uncommon.

Emerging information about Giardia typing and zoonotic disease risks shows that this is a more complex issue than previously thought. Studies that determine the prevalence of Giardia shedding in dogs and cats are useful, but they only tell part of the story. Comments about the human health implications of Giardia shedding in pets can only be made when information about the Giardia assemblages found in these animals is also reported.

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

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In the same edition of Emerging Infectious Diseases as a report on Campylobacter jejuni in macaroni penguins in Antarctica, there is a report about vancomycin-resistant enterococci (VRE) in glaucous gulls in Point Barrow, a remote area of Alaska.

Vancomycin-resistant enterococci are an important problem in human medicine, mainly in hospitals where they can cause sporadic infections and outbreaks of infection. These infections can be difficult to treat because VRE is resistant to many antibiotics, including vancomycin. VRE is not very common in animals in North America at this time, but there is concern that it could be an emerging problem, because as VRE rates in people increase the bacterium gets spread more commonly to animals. There have been many more reports of VRE in animals in Europe. This has been largely attributed to the widespread use of avoparcin (a drug related to vancomycin) as a growth promoter in food animals in Europe, a practice that was common until the mid 1990s, but is now banned in many countries.

This study demonstrates that organisms like VRE can be spread to wildlife in one of the most remote regions of North America. As the authors state "This spread suggests that few (if any) places on earth may be protected against the spread of such resistance, and the dispersal mechanisms are far more efficient than previously thought."

These two reports show how well (and expectedly) infectious agents can travel. They are also good examples of why we need to be thinking globally, ecologically and truly in the mindset of “one medicine” if we really want to understand infectious diseases.

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...Macaroni penguins, that is. There is a report in a recent edition of Emerging Infectious Diseases about isolation of Campylobacter jejuni from Macaroni penguins in Antarctica. Campylobacter is a bacterium that can cause diarrhea in people and animals, and which can also be found in the intestinal tracts of a wide variety of animal species, even when they’re healthy. Researchers typed the Campylobacter isolates from a group of penguins in Antarctica and found that many were a strain that commonly affects people. They had a few different ideas about how the penguins became infected. One possibility is contamination from toilet wastes that a nearby research station dumped into the surrounding water. They thought that ships discharging sewage into the ocean near the penguins' feeding grounds could also be a source of the bacteria, as could migratory birds like albatrosses that spend part of the year closer to people. Whatever way it got there, a penguin colony provides an exceptional opportunity for Campylobacter to spread, since huge numbers of penguins live in very close proximity to each other. Fortunately, Campylobacter rarely causes disease in birds, and we hope that's true with this strain in penguins as well.

This report shows how closely linked humans and animals can be, even when we usually live far apart. It also shows why we keep saying that a global ecological approach to infectious diseases is needed - we need to look at the big picture.

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

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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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Another surge in the number of cases of Q fever in people in the Netherlands has been reported.  Prior to 2007, the average number of cases of Q fever per year in the country was only 15.  In 2007 there were 192 cases, and last year there were 958 cases, making this the largest community outbreak of Q fever ever reported.  At the beginning of May 2009, another jump in the number of cases - over 200 - was reported by the dutch newspaper de Volkskrant.

Q fever is caused by a highly infectious organism called Coxiella burnetii.  The organism can be carried by many different animals, but particular sheep and goats, and sometimes cattle.  Most of the time it does not cause a problem in these species, but it has been linked to abortions and abortion storms (i.e. when many animals in the herd abort in a short period of time).  It can be shed in manure, urine and milk, but the largest numbers of organisms are found in birth fluids and tissues (e.g. aborted fetuses, placentae).  When the tissues and fluid dry out, the organism can be stirred up into the air over short distances in dust.  Humans are highly susceptible to C. burnetii, and inhaling even a single organism can cause infection.  Most of the time people who get sick have signs very similar to the flu, but severe pneumonia and liver disease can develop in a small number of cases.

A definitive link between sheep and goats and the Q fever outbreak in people in the Netherlands has not yet been established, but it is highly suspected that many of the cases are associated with infected goats (and some sheep).  In the last two years numerous outbreaks of Q fever have been reported on dairy goat farms and one dairy sheep farm in the Netherlands.  This has lead to a cooperative arrangement between the Dutch agricultural ministry and the Dutch public health ministry - these two goverment branches have come together to help cover the costs of vaccinating sheep and goat herds in the country, in order to help stem the tide of disease and ultimately prevent more human cases.  This is a great example of the "one medicine" concept, whereby groups on both the human health and agricultural/animal health sides are working together on this problem.

Manditory vacciation is now required for sheep and goats on larger farms in the hardest-hit areas, as well as any farms reporting any cases of Q fever since 2005, and any sheep or goats that have a "public function" (e.g. petting zoo animals or occupational therapy farms).  It is very important that this last group is included under the manditory vaccination, as these animals have a large amount of contact with people.  Steps have also been taken to improve hygiene, restrict spreading manure from sheep and goats, restrict visitors to infected farms, and to make abortion storms on sheep and goat farms reportable, so they can be investigated for Q fever.  It will be interesting to see how effective these measures are at controling the outbreak in 2009.

More information on Q fever can be found in our archives.

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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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