"Pet" bat bites child
A woman from Kansas was cited for keeping exotic pets within city limits after her son was bitten by one of the family's pet bats. The bats were confiscated and will be tested for rabies.
Some animals make good pets, some are mediocre and some are completely inappropriate. Bats are in the last category. Bats are the main vector for rabies virus in North America and they do not have to look sick to be carrying rabies. Bats can bite when being handled and bites are often very small, so they are not always taken care of or even noticed. A person not reporting a seemingly harmless bat bite is a common history in human rabies cases.
Even if rabies didn't exist, keeping pet bats would still be a bad idea. Bats are very difficult to care for properly, and rarely survive for long in captivity, except in well-run zoos with excellent facilities and very knowledgeable caretakers.
More information on rabies is available on our Resources page.
Check out the new information sheets about Clostridium difficile now available on the Resources page!
Rabies infection in adopted Iraqi dog
Another incident of importation of a dog with rabies has been reported. A number of dogs have been brought home by US soldiers, and a few cases of rabies have been found. In the latest case, rabies was diagnosed in 1 of a group of 26 dogs that was flown back to the US to join returning soldiers. All customs and health regulations were followed, but rabies was diagnosed in the dog approximately 3 weeks after arrival.
This incident highlights a few things, including the fact that rabies, even in dogs, can be quite common in some areas of the world, and that movement of animals across borders may increase the risk of introducing infectious diseases. Certainly, cases such as this should not be used to say that these dogs should not be adopted. Rabies (or other serious disease) is a rare event in these situations, and the overall risks to people are minimal if proper procedures are followed. This includes making sure that all animals remain accounted for after arrival, and pursing proper diagnostic testing in the event that they show signs of illness (as was done here). The other dogs that came back with the rabid dog are being monitored. The risk of transmission from this dog to the others is quite low, since it is unlikely that the dog was able to transmit rabies 3 weeks ago, well in advance of developing signs of disease. In some cases it can be weeks to months from the time a dog (or other animal) is exposed to rabies until they become infectious to others. Presumably, people that had contact with this dog recently are now undergoing post-exposure treatment.
More information about rabies can be found on the Worms & Germs Resources page.
Tapeworms in dogs and cats
Finding a tapeworm in a pet's stool can be a concerning event for some people. Tapeworms are intestinal parasites that can be found in varying percentages of dogs and cats. A common tapeworm (at least in North America) in dogs and cats is called Dipylidium caninum, and it can be found in a high proportion of dogs and cats in some regions, particularly animals that go outside and are infested with fleas. There is minimal concern about transmission of this tapeworm to people. Taenia pisiformis (dogs) and Taenia taeniaeformis (cats) are also common, and neither of these can infect people. 
People typically realize their pet has tapeworms when they see small tapeworm segments in the animal's stool. These whitish, rice-sized pieces (called proglottids, see the picture on the right) are parts of the adult tapeworm, which break off and are passed in the stool.
Tapeworms are not usually harmful to dogs and cats, particularly if only one or a few worms are present. In some situations, weight loss can occur. Affected animals may 'scoot' (drag their rear end across the ground) because of irritation from tapeworm segments that are passed in the stool.
Diagnosis of a tapeworm infestation is easiest through identification of tapeworm segments in stool. Identification of tapeworm eggs in stool samples through routine testing used for other intestinal parasites is less useful, as the bare eggs are infrequently shed in stool. Therefore, a negative fecal egg examination does not rule out tapeworms.
Dipylidium infections are extremely rare in people. Children are at greatest risk. Disease in people, if present, is usually mild and easily treated. However, finding tapeworms in a person's stool can be distressing to the individual (and their family). Dipylidium cannot be transmitted directly from animals to people. People and pets get infected by ingesting a flea that is infected with tapeworm larvae. Therefore, flea control is the most important aspect of tapeworm prevention. People that find tapeworm segments in their stool should contact their physician to determine whether they are actually tapeworms (people often mistake other things for tapeworm segments) and to determine whether any treatment is needed.
There are specific dewormers that can be prescribed by your veterinarian to eliminate tapeworms in pets. It is also important to take measures to control fleas and prevent dogs and cats from catching and eating animals that might be carrying fleas.
Cat bites - Why it's not "just a scratch"
Even the most well-natured, lovable cat has the potential to bite. Particularly if an animal is frightened or in pain, it may lash out with teeth and claws, even at its most trusted human companion. Many of us are used to sustaining small cuts and wounds in everyday life, and at times it hardly seems worthwhile to trouble a physician to look at a little cat bite. But 20-50% of cat bites become infected, compared to 4-20% of dog bites. The bacteria responsible are most often combinations of Pasteurella spp., Staphylococcus spp., Streptococcus spp. and others. In some cases, particularly when Pasteurella multocida is involved, the infection can develop very rapidly (within hours) and may become very serious, or even spread to the bloodstream. Cat scratch disease (Bartonella henselae infection), despite the name, can also be transmitted by cat bites. Cat bites can be very deep, even though they look very small at the level of the skin, which may lead to infection of things like joints and tendons under the skin, which are more serious.
You should see a doctor about any cat bite on a hand, over a joint, over a tendon sheath (such as the wrist or ankle), over a prosthesis or implant, in the genital area, or that causes a deep tear. You should also see a doctor for any bite if you happen to have a weakened immune system for any reason (e.g. HIV/AIDS, cancer or transplant patients).
The best way to prevent infection is to prevent the cat from biting you in the first place!
- Use common sense – know how to handle a cat properly so that it is not frightened or uncomfortable. If a cat growls at you or tries to get away, let it go!
- Don’t let cats play with your hands, feet or hair. Use a nice cat toy instead.
- Don’t approach strange cats, especially strays. If you are bitten by a cat that may not have been vaccinated for rabies, it is very important to report the incident to you local public health department and your doctor, as you may need to receive rabies post-exposure prophylaxis (PEP).
Rabies awareness month
June has been declared Rabies Awareness Month in New York State. The focus of the occasion is on education, particularly with respect to bats. Since 1990, 38 of 41 human rabies cases in the US involved bats. Approximately one-third of bats tested in New York are positive for rabies. In 2007, 559 animals were confirmed as infected with rabies in New York, and more than 3000 people were treated for rabies exposure. Further, more than 1400 New Yorkers undergo treatment each year following exposure to bats that were not caught and tested. State health personnel are emphasizing the need to catch and test bats if people have had contact with them, or when a bat has been present in a house with a sleeping person. They have produced a video on how to safely catch a bat in the house.
Important points to remember about rabies and bats are:
.jpg)
Never touch a bat.- Consider every bat to have rabies until proven otherwise.
- If you have slept in a house overnight with a bat, you are considered exposed. Unless the bat is caught and tested (and shown to be negative) you should undergo post-exposure treatment.
- If you or your pet may have been in contact with a bat, try to catch it (safely) so that it can be tested for rabies.
- Vaccinate your pets against rabies, even if they never leave the house.
Photo: Little brown bat (M.B. Fenton)
EU Antibiotic Awareness Day
The European Union has announced that November 18 will be the EU's Antibiotic Awareness Day.
Antibiotics are incredibly important drugs and save countless lives (human and animal) on a daily basis. Resistance to antibiotics is a major threat to human and veterinary medicine. While antibiotic resistance is a complex issue, overuse and improper use (in animals and people) undoubtedly contribute to the emergence and spread of resistant bacteria like MRSA. Awareness of these concerns is important for healthcare professionals (both human physicians and vets) and the general public. Here are some general points to remember with respect to pets and antibiotics:
- Do not encourage your vet to prescribe antibiotics when they are not necessary. Vets (and physicians) often feel pressure to prescribe 'something', even though they have no clear evidence of a bacterial infection. Antibiotics do not work for viral infections.
- Never give antibiotics to your pet without the direction of your vet.
- Always give the full antibiotic course, as prescribed. Do not stop early. Your pet may look better but the infection could still be there.
- Never save antibiotics for 'future use'. If your pet develops another infection, you need to have your pet evaluated by a vet to determine if antibiotics are needed, and what antibiotic would be best.
Tularemia Trouble
A case of pneumonic tularemia was recently reported in New York City.
Tularemia is a disease caused by the bacterium Francisella tularensis. It causes different signs of illness depending on how the bacteria enter the body. If the bacteria are inhaled, it tends to cause pneumonia (pneumonic tularemia). If the bacteria get in through a break in the skin, infection may cause the local lymph nodes (glands) to become very swollen, and in some cases the skin itself may become infected resulting in the formation of large sores (ulcers). Infection can also cause sores in the mouth and diarrhea. The earliest, most common signs are things like fever, headache, chills, sore muscles, and sore throat which often come on very abruptly. The infection can be treated with antibiotics, but it is important to see a doctor and start treatment as soon as possible.
Tularemia is also sometimes called "rabbit fever," because the bacteria are often carried by animals such as rabbits and hares. Rodents (including beavers, rats, mice, squirrels etc.) can also carry F. tularensis, and occasionally so can cats and dogs. Some biting insects like deerflies and certain species of ticks can carry the bacteria and transmit it when they bite. Francisella tularensis can also survive in water and soil for a long time. People can become infected by being bitten by an infected insect, handling an infected animal (dead or alive), or coming into contact with feces from an infected animal. Occasionally a person may inhale the bacteria if it is in the air, as may happen with disturbed, dusty, contaminated soil.
More information on tularemia can be found on the CDC's tularemia website.
Things you can do to avoid tularemia:
Avoid touching or handling wildlife (dead or alive), especially rabbits and rodents.
Don't let your pet touch or eat dead animals.
Always wash your hands if you have been working outside in the dirt/soil.
Wear insect repellent containing DEET (visit the Health Canada website for more safety tips)
Make sure you only wash food with and drink water that has been properly treated.
One of the reasons tularemia is such a big deal is it is very infectious - as few a ten bacteria can be enough to make even a healthy person sick! But it is still quite uncommon in North America - about 100-200 cases are reported in people in the USA every year. Between 2002-2004 there were 34 cases reported in Canada, most of which occurred in Quebec and in adults. However, infection can be fatal in a very small number of cases, especially if proper treatment is not given as soon as possible.
Dogs and dead birds
As the owner of a dog that loves to roll in (and eat) anything she finds, I certainly understand the questions that I get about risks to dogs from dead birds. Eating a dead bird is certainly not an appealing thought to us, but overall, the risks to a dog are pretty low. The greatest potential problem is likely gastroenteritis, often referred to as ‘garbage-gut’, which typically causes diarrhea (with or without vomiting) after "dietary indiscretion" (i.e. a dog eating things it shouldn't have). Another concern is Salmonella. Some birds carry Salmonella in their intestinal tracts and dogs could become infected from eating them. This is a bigger problem in cats that hunt birds - salmonellosis in outdoor cats is also referred to as songbird fever. West Nile virus can cause death in birds, especially species such as bluejays and crows, which may then be found by your dog. The risk of transmission of West Nile virus to dogs from eating dead birds is presumably very low. Further, this disease is very rare in dogs and they appear to be quite resistant to the virus.
- Try to prevent your pet from eating/touching dead birds.
- If your pet develops diarrhea after eating a dead bird, it is probably not a health concern for anyone else but Salmonella infection is possible, so consider taking your dog to the veterinarian. This is especially important if the dog appears sick (i.e. besides vomiting and diarrhea, the dog also is not acting like itself) or if there are people in the household that are at higher risk for getting sick from bugs like Salmonella (i.e. infants, people with weakened immune systems). All diarrhea should be considered potentially infectious to other animals and people. Extra care should be taken around affected pets and their stool, including extra attention to hand washing, and disinfecting the site of any "accidents" that occur in the house.
- In some areas where bird testing is performed for West Nile virus or avian influenza surveillance, public health personnel will collect dead birds. Contact your public health department if you are unsure what is done in your region.
- Do not touch dead birds with bare hands.
- Use heavy-duty, leak-proof gloves to place the bird in a leak-proof plastic bag. Alternatively, fold two bags over your hand and use the bag to cover your hand when picking up the bird (like people do when poop-scooping), or use a shovel to place the bird in a bag.
- Double bag the bird.
- If the bird is not being collected for testing, contact your local waste management agency regarding disposal instructions.
- Always wash your hands with soap and water as soon as you're done.
Toxoplasmosis - Why Your Cat Shouldn't Get the Blame or the Boot
Toxoplasma gondii is one of the most widespread zoonotic pathogens in the world. Toxoplasma is a protozoal parasite that can infect almost any warm-blooded animal, including humans. In most people and animals, infection doesn’t cause any illness at all, and after the initial infection, the body usually produces strong immunity which protects it from subsequent Toxoplasma infection. Problems arise when infection occurs in a person with a weakened immune system. For example, toxoplasmosis (i.e. illness due to Toxoplasma) has been a major problem in HIV/AIDS patients, although better HIV treatments have decrased the incidence of the disease in this group in recent years. Toxoplasma can also cause problems when a woman is infected for the first time, before her body has developed immunity to the parasite, while she is pregnant. In these cases, the parasite can infect the fetus. This may result in birth defects or loss of the pregnancy altogether.
Our friendly feline companions have the unfortunate distinction of being what is called the “definitive host” of Toxoplasma. This means that even though the parasite can infect many species of animals, cats are the only species that shed the parasite “eggs” (which are called oocysts in this case) in their stool after they’re infected. But what most people don’t realize is that the number of cats that are shedding oocysts at any one time is very small – usually less than 1 in 100. And after the first time a cat is infected, it usually doesn’t shed oocysts again, and if it does it sheds them in very low numbers.
Depending on individual lifestyle and eating habits, a person is just as likely or more likely to be exposed to Toxoplasma from working in the garden or eating undercooked meat (particularly free-range pork or wild game). People who are pregnant or who have a weakened immune system do NOT need to get rid of their cats because of Toxoplasma, but they DO need to take steps to avoid exposure to Toxoplasma from all sources. This includes avoiding contact with cat stool and kitty litter by asking someone else to clean their cat’s litter box for them if possible, or wearing rubber gloves and being very careful to wash their hand very well afterwards if they need to clean the box themselves. Here are a few more tips that can help reduce their risk of exposure to Toxoplasma:
- Clean your cat’s litter box every day. The oocysts usually take about 24 hours to become infective once they’ve been passed in your cat’s stool, so daily cleaning helps remove them before they reach this stage.
- Always wash your hands with soap and water after cleaning your cat’s litter box, after working in the garden or in any soil, and after handling raw meat.
- Cook all meat, especially pork, lamb, mutton and wild game, to an internal temperature of 67ºC/153ºF or higher.
- Keep sandboxes covered so outdoor cats don’t contaminate them with stool.
- Keep your cat indoors. Outdoor cats are more likely to be exposed to Toxoplasma and shed oocysts in their stool.
Removing ticks
As we (finally) get nice weather here, a rash of questions about ticks usually follows. Ticks are very common in some areas, and a short walk in the woods can result in exposure. Ticks themselves aren't the concern. The problem is infectious diseases that ticks can transmit, including Lyme disease. The risk and types of diseases of concern vary geographically. (In Ontario, exposure to ticks that can transmit Lyme disease is most common in Point Pelee, Rondeau, Long Point, Turkey Point and the Thousand Islands area). There are a number of ticks that may feed on people and pets, but only a few that transmit infections. 
Your veterinarian, physician and/or public health departments should be able to tell you what diseases are of concern in your area.
Regardless of where you live, if you and your pet might encounter ticks, you should know how to remove them. Prompt removal is the key. Most tickborne diseases aren't transmitted immediately. Rather, the tick must be attached for a period of time for infection to occur. Therefore, close inspection of your pet (and yourself) for ticks after spending time outside, is important.
The following tick removal tips come from the Centers for Disease Control and Prevention (CDC).
- Remove a tick as soon as you see it.
- Use fine-tipped tweezers to firmly grasp the tick very close to your skin. With a steady motion, pull the tick away from your skin. Then clean your skin with soap and warm water.
- Avoid crushing the tick’s body.
- Do not be alarmed if the tick’s mouthparts remain in the skin. Once the mouthparts are removed from the rest of the tick, it can no longer transmit Lyme disease bacteria.
- If you accidentally crush the tick, clean your skin with soap and warm water or alcohol.
If a large number ticks are present on your pet, you should contact your veterinarian for assistance. Typically, a product that kills ticks will be applied to your pet.
There are various anecdotal recommendations that should be avoided, including burning the tick off with a match and covering the tick with substances such as gasoline, petroleum jelly or nail polish.
Dog stool and garbage
I received the following question yesterday:
For approximately 20 years I have been involved in waste collection for the Parks Division. A considerable amount of the waste which I collect on a daily basis is dog excrement. This is usually, but not always contained in a plastic bag and thrown into a large garbage barrel which I man-handle and dump in a waste truck. Years ago I contacted the local Health Unit and asked if there was any special health risks associated with this job. They advised me at that time the main danger to health would be with E.coli contamination. I use neoprene gloves while carrying out my duties and of course try to ensure that I do not come in contact with any debris. This is not always possible.
There are 3 main risks with handling dog stool: exposure to bacteria that cause diarrhea, exposure to intestinal parasites and infection of wounds.
Various bacteria that can cause diarrhea can be present in dog stool. These include Salmonella and Campylobacter. E. coli is not a major concern because strains found in dogs are not typically those that cause disease in people. A few intestinal parasites are also of concern, including Giardia and roundworms. The risk of exposure to these is hard to say because you don't know anything about the health status of the dogs, but it's wise to treat all stool as infectious. However, for these to cause disease, they must go from the garbage and into your mouth. The risk of this should be minimal with basic common-sense precautions.
A large number of bacteria present in stool can cause infections of wounds like cuts and scratches, or other skin lesions such as eczema. Direct contact of these lesions with stool would be required to cause infection. The risks of this can also be greatly reduced with basic preventative measures.
Some basic precautions (many of which you are doing) include:
- Wear gloves when handling bags containing stool.
- Change your gloves if they become contaminated with stool.
- Have your gloves cleaned periodically, and whenever they become contaminated. Otherwise, use disposable gloves.
- Promptly wash or disinfect your hands if they become contaminated. Carrying an alcohol-based hand sanitizer in your truck would be useful.
- Wear coveralls or some other sort of outerwear that can be removed easily if contaminated. If your clothing becomes contaminated, change it (and wash your hands after).
- Wash your hands after removing your gloves (and especially before eating).
Overall, the risks to you should be very low.
Methicillin-resistant staph: what's in a name?
There is a lot of concern and confusion about methicillin-resistant staphylococcal infections in pets. "Staphylococcus" is genus of bacteria which contains numerous different species. All these species can come in 'methicillin-resistant' forms that are resistant to many antibiotics, but some of these species are of greater concern than others. The main species of concern are discussed below.
Methicillin-resistant S. aureus (MRSA): This species is the big concern. MRSA is an important cause of disease in people and an increasing problem in pets. It can cause serious infections and be transmitted between animals and people (in both directions).
Methicillin-resistant S. intermedius (MRSI): Actually, what most laboratories still call S. intermedius appears to be a related species called S. pseudintermedius. Regardless, MRSI (or MRSP) can cause a variety of infections in pets - usually skin and ear infections. While it can be spread from animals to people, this is likely rare and there is much less concern about MRSI compared to MRSA in terms of risk to humans from infected pets.
Methicillin-resistant S. schleiferi (MRSS): This species is closely related to (and often misidentified) as S. intermedius. It is most commonly found in skin and ear infections. There is no information about the risk of transmission to people from pets. It is probably possible but very unlikely.
Methicillin-resistant coagulase-negative staphylococci: This is a large group of staphylococcal species that are usually lumped together. They are commonly found in or on healthy dogs and cats as part of the body's normal bacterial population. They are less common causes of disease. There is currently minimal concern about transmission to humans.
MRSA is the main concern with regard to staph infections, and warrants particular attention when it causes infection in a pet. In these cases, important precautions to take include washing your hands frequently, avoiding contact with the infected part of the animal's body (plus the nose, where MRSA often hangs out), keeping the infected site(s) bandaged (if possible), keeping infected pets off the bed, and restricting contact with high risk people (e.g. young children, elderly, immunocompromised). For the other staph species, the risks to people are much lower, but it is still reasonable to implement these measures to further reduce the risks.
Rabies kills...vaccinate your pets!
A recent report from South Carolina stated that 3 cats were euthanized because they were exposed to
a rabid raccoon. One of the cats was acting strangely and may have actually been infected with rabies (it is being tested). The other two cats appeared healthy, but none of them had been vaccinated for rabies, so the only options were to euthanize the animals or quarantine them for 6 months. In South Carolina, such a quarantine entails keeping the animals at a veterinary clinic or in a cage in an isolated room or yard, 24 hour a day. The owners did not want to quarantine the cats so they chose to have them euthanized instead. If the cats had been vaccinated, a much shorter and easier quarantine period could have been applied. Rabies vaccination is a cheap, easy and effective way of protecting pets and the public.
If you care about your family and your pets, vaccinate you pets against rabies.
More information about rabies is available in our Resources page.
I've been diagnosed with MRSA....could my pet be the source?
Methicillin-resistant Staphylococcus aureus (MRSA) is a multidrug resistant bacterium that is often referred to as a 'superbug'. It is an important cause of disease in people, both in hospitals and in the general population. It can also infect various animal species, including dogs and cats. A small percentage of healthy people and animals (1-3%) carry MRSA without knowing it, and usually without ever having any problems. Unfortunately, increasing awareness of the potential for healthy pets to carry MRSA has led to excessive focus on pets in some situations. While transmission of MRSA between people and pets can happen, it is probably more common for it to go from people to pets, than pets to people. Pets should not be 'blamed' for human MRSA infections without good evidence, and there are only certain situations where evaluating pets is currently indicated.
Here are some important points from the Canadian guidelines for management of community-associated MRSA in people.
- Testing of pets for MRSA carriage should only be considered when there is recurrent MRSA in the household and transmission is ongoing despite the implementation of household infection control measures.
- Testing of pets should only be done as part of an overall investigation of the household. Testing of pets but not human household contacts is not indicated.
- Removal of the pet should only be considered in exceptional circumstances, and removal should be temporary. Such circumstances could include households where controlling contact with the pet is not possible and/or when people in the household are being treated to eliminate MRSA carriage. The beneficial effects of pet contact should be considered in any discussion about removal of the pet from the household.
Stray kittens
While visiting my parents this weekend, we came across a litter of stray kittens in the backyard. This is not an uncommon event and many people obtain their cats this way. Adopting stray kittens can be a great way to get a cat because it provides a good home for kittens that would otherwise end up increasing the feral cat population. However, there are some things to consider to reduce the risks to your family and your other pets.
Various bacteria that can cause diarrhea in people can be carried by kittens, including Salmonella and Campylobacter. These are shed in the stool of infected animals, and people can become ill from handling the animal or stool-contaminated areas. Kittens may have higher rates of carriage of these bacteria than adult cats. Another bacterium that can be carried commonly by kittens is Bartonella henselae, the cause of cat scratch disease. This is transmitted by bites, scratches and fleas, and is just one reason for proper flea control.
Stray kittens are also more likely to carry Toxoplasma, a parasite that is a concern in pregnant women and immunocompromised individuals. Other intestinal parasites such a roundworms are also a concern. Kittens are more likely to have these parasites than adult cats. Stool contamination of the haircoat is presumably more common in kittens as well because they are not as good about cleaning themselves as adult cats. So just handling a kitten, even if you avoid its stool, may result in exposure to some of these parasites and bacteria.
Rabies is always a concern, and widespread exposure of people to rabies has occurred from infected litters of kittens. While uncommon, rabies is a major concern because it is almost invariably fatal. Any stray (or recently rescued) animal that starts acting strangely should be considered a rabies-suspect and be taken to a vet immediately. [More information on rabies, and other topics, is available in our Resources page].
Stray kittens can also carry various infectious diseases that can be transmitted to other cats in the household, such as feline leukemia virus, panleukopenia, rhinotracheitis and calicivirus.
Overall, the risks from adopting stray kittens are low, but they are real. If you are going to adopt/rescue a stray kitten, keep these things in mind:
- Take the kitten to your vet as soon as possible to identify any health issues and determine the required vaccination, deworming and flea control program
- Wash your hands after handling the new kitten
- Keep the new kitten in a confined area while litterbox training is underway to reduce accidents throughout the house
- If you have another cat, make sure it is up-to-date on vaccinations before the kitten comes into the house.
- If the kitten gets sick, make sure it is taken to a vet. If it dies suddenly, make sure you take it to your vet to determine whether testing for rabies is required.
- Pregnant women and households with immunocompromised individuals should not adopt stray kittens.
Reptile shows....wash your hands!!
Last weekend, my family and I went to an (indoor) aviary for an outing because the weather was particularly miserable. A new addition to this facility was a large reptile encounter exhibit. As part of this, people were encouraged to handle a bearded dragon (a type of lizard) and a large python. Contact with the animals was extremely popular with most people, including one of my daughters. She held the snake (twice) and the bearded dragon. Part of me was enjoying the experience and seeing what she got out of the encounter, but the infectious disease side of me had some concerns.
Petting zoos and similar animal contact events carry an inherent risk of infectious disease transmission. Outbreaks of various infectious diseases have been reported, mainly associated with farm animals. Reptiles are a particular concern because they can have high rates of Salmonella carriage. Terrestrial reptiles like bearded dragons and pythons are lower risk than species like aquatic turtles, but these animals can still be the source of salmonellosis in humans.
Petting zoos can be entertaining and educational, and fairly safe if run properly. However, deficiencies are often present. At this facility, there were multiple hand hygiene stations, consisting of alcohol-based hand sanitizers, which are very effective. Food and drink were banned in the area and there were staff supervising all animal contacts. These are all good things, however the best measures are useless if they are not used or enforced. While I made sure that my family carefully cleaned their hands, we were definitely in the minority. The hand hygiene stations were not particularly easy to access and there was't one present at the exit, so if you weren't looking for it you would probably just leave. Further, despite the signs, staff allowed people to eat and drink in the area where they were handling reptiles. Allowing people to eat and drink, and not providing easy access to the hand sanitizers (two pretty basic measures) were major problems and greatly increase the risk of disease transmission.
I'm not suggesting we should avoid petting zoos. My kids enjoy them and we will surely attend a few this summer. The key with animal contact exhibits is common sense....avoid high risk animals, keep you hands out of your mouth and wash your hands thoroughly when leaving (even if you didn't touch an animal since you probably touched other surfaces). Some animal species are particularly high risk, including young poultry and young ruminants (e.g. calves, lambs, goats). Reptiles fit into this high risk group, which is why I had more concern about this event than a standard petting zoo. People with compromised immune systems should avoid animal contact, particularly with calves, chicks, lambs and reptiles.
And above all, WASH YOUR HANDS.
A good source of information about animal contact events and infectious diseases is available from the National Association of State Public Health Veterinarians.
Salmonella-contaminated pet food
The CDC has released the findings of an investigation of a prolonged multistate outbreak of salmonellosis that was linked to dry dog food in 2006-2007. This outbreak implicated two different dog food brands, both made by the same manufacturer in the same plant in Pennsylvania, as the source of a particular strain of Salmonella Schwarzengrund. The strain infected numerous people, and was also found in some dry dog food samples and stool samples of dogs that were fed the food, with which the affected people had had contact. No illness was reported in the pets. It is unclear whether people were infected from contact with the food or contact with the pets' stool.
This is the first report of salmonellosis associated with dry pet food. Previous outbreaks have been associated with contact with raw pet treats such as pig's ears. Overall, the risk from contact with dry pet food is quite low, although this outbreak clearly demonstrates that some risk exists. Handwashing after contact with pet food should greatly reduce the already low risk.
This report is certainly not a reason not to feed your dog or cat a commercial pet food. One concern that I have is that this report will (and already seems to) be used by proponents of raw meat diets as support for this feeding practice. Feeding of raw meat has been clearly shown to increase the rates of shedding of potentially dangerous bacteria such as Salmonella. Illness and death from these bacteria have been identified in dogs fed raw meat. The high rates of Salmonella shedding in raw-fed dogs are a significant public health concern, and these concerns have been previously reviewed. Outbreaks of human salmonellosis have not been reported in association with raw meat feeding. This could indicate minimal risk, but could equally be due to lack of identification of sporadic cases that would be more likely with raw food than large-batch commercial contamination or better hand hygiene practices associated with raw meat handling.
- The risk of Salmonella exposure is still much lower with good quality commercial pet food compared to raw meat.
- Wash your hands after handling pet food (of any variety), as well as food and water bowls.
- Care should be taken when handling animal stool to avoid any direct contact with it. Wash your hands after picking/cleaning up any type of stool, even if you use a plastic bag or a designated scoop to do so.
West Nile virus in dogs and cats
One thing that has become very clear around my house the past few days is that mosquito season has arrived. Along with the annoyance, buzzing and itching, mosquitoes are of concern because they can transmit various viruses, including West Nile virus. While West Nile season tends to be later in the summer and fall in most regions, West Nile virus awareness and mosquito bite avoidance should be considered whenever mosquitoes are around. 
Most of the attention about West Nile virus has been paid to humans, horses and birds, because of widespread illness and death in those species. Dogs and cats can certainly be exposed to West Nile virus if they are bitten by an infected mosquito; just like people and other animals. However, there are very few reports of West Nile virus infection in dogs, and even fewer in cats. Most dogs and cats that are infected do not develop signs of disease and simply develop antibodies against the virus.
Even if dogs or cats develop West Nile virus infection, there is no risk of transmission to other animals or human. This is because there is never a large enough amount of virus in the blood of these animals for a mosquito to pick it up and transmit it to another animal or person. The virus also can't be transmitted by direct contact with an infected dog or cat. West Nile virus is not found in saliva, so it is also unlikely to be transmitted by an animal (instead of an insect) bite.
There is no reason to be concerned about transmission of West Nile virus from your pets. If you live an area where West Nile virus is present, you should take precautions to avoid mosquito bites, such as avoiding mosquito-dense areas, wearing insect repellent with DEET, wearing long pants, long sleeves and socks when outside, avoiding peak mosquito hours (dusk and dawn) and eliminating any areas of standing water where mosquitoes can breed.
Pets and strep throat
Another question that I periodically get asked is about pets (mainly dogs) and strep throat. The usual situation is a household where there has been strep throat in multiple family members or where someone, usually a child, has had repeated bouts of strep throat. People ask whether their pet could be the source.
Strep throat is caused by Group A Streptococcus, a bacterium that can be found in the throat and on the skin of some healthy people. Strep throat and impetigo are the most common diseases caused by Group A Streptococcus, although severe (‘invasive’) infections can occur, including ‘flesh-eating disease’. Group A Streptococcus is typically spread between people, both from people that are sick and healthy carriers.
Group A Streptococcus carriage by dogs and cats is extremely rare, and it is unlikely that they are involved in transmission to people. There were some older studies implicating dogs in transmission of Group A Strep, however there were weaknesses in the methods used by those studies which probably lead them to misidentify other types of Streptococcus that are often found in dogs as Group A Streptococcus. There is currently no convincing evidence that pets are a source of strep throat infection, although the possibility cannot be completed dismissed.
I have had questions about treatment of pets when recurrent strep throat infections were present in a household, which is not supported by any evidence and could lead to problems like antibiotic resistance and side-effects from antibiotic use such as diarrhea. It’s hard to say whether there is any indication to test dogs or cats when recurrent strep throat is present in a household. Collection of a throat swab by a veterinarian and culture of the swab is fairly easy to do. It’s not unreasonable to consider that but a few things must be remembered:
- Even if Group A Streptococcus is found in a pet, it does not mean that the pet is spreading it. The pet might just be an ‘innocent bystander’ that was infected by a family member. It makes no sense to test the pet if the rest of the household is not being tested.
- Proper identification must be performed by the laboratory to differentiate Group A Strep from other strep. Just finding ‘Streptococcus’ is not useful.
- There are no guidelines for what to do in the unlikely event that a pet is identified as a carrier.
Overall, pets are not likely a major (or even minor) source of strep throat. If strep throat is circulating within a household, it's most likely being spread between people.
Parvovirus and Fifth Disease
Numerous outbreaks of Fifth Disease have been reported internationally. That, itself, is not particularly newsworthy because outbreaks are quite common and disease is typically mild. In children, Fifth Disease typically causes a rash on the face, trunk and limbs. The sa
me type of rash can occur in adults, as can joint point or swelling. Severe complications can develop in pregnant women. There is no vaccine. Fifth Disease is caused by Parvovirus B19, a fact that sometimes leads to questions about dogs because of peoples' awareness about canine parvovirus.
Canine parvovirus is a highly infectious cause of life-threatening diarrhea in dogs, mainly puppies. Canine parvovirus vaccination is a very important component of routine vaccines for dogs.
Questions often arise about whether dogs can be a source of Fifth Disease, or whether people with this disease can infect dogs. The parvovirus that causes Fifth Disease is not the same virus that causes disease in dogs. Human parvovirus cannot infect dogs, nor vice versa.
An interesting fact about Fifth Disease is the origin of its name. The name originates from a standard list of causes of rash from the early 1900s. This condition was the fifth on the list, and for some reason, it became known as ‘Fifth Disease’. None of the other disease were named by their ranking.
Public Domain image from Wikimedia.org
Keep the 'wild' in 'wildlife'
Sixteen people in South Carolina are undergoing rabies post-exposure treatment after having contact with a rabid baby raccoon. Additionally, 20 of their pets are undergoing quarantine.
Wildlife should be left in the wild. While some wild animals, especially babies, are hard to resist, little good usually comes from intervention of the general public. This is particularly true when well meaning people ‘rescue’ baby wildlife. Often, ‘orphaned’ wildlife are not orphans; the parents are hiding nearby and would have returned. Few animal facilities are properly equipped or licensed to properly deal with wildlife, and these ‘rescued’ orphans often end up being euthanized. Some people try to nurse these animals themselves but few can do it properly. It’s also illegal in many areas. Add that to the obvious risk of rabies, as highlighted here, and it should be clear that wildlife should be left alone. It’s also a good reminder of the need to vaccinate your pets because rabies exposure can occur in many different ways. The pets in this situation are reportedly under 45 day quarantine, which is certainly not something you want to do, but is much better than what would happen in many jurisdictions in the case of rabies exposure of an unvaccinated pet (long strict quarantine or euthanasia).
Baby raccoons are very cute and hard to resist, but like many other forms of temptation, danger, in this case in the form of infectious diseases, can lurk just around the corner. More information on rabies is available in our Resources section.
Camping with canines - tick tick not!
The warm weather is just about here, and that means the start of camping season. Lots of people love to spend time in the great outdoors during the summer, whether it’s at a summer cottage on the lake, trailer camping in a park with electricity and running water, or roughing it in a tent in the peace and solitude of a more remote wooded location. And many people bring along their faithful companions – their dogs – who enjoy the experience just as much, if not more, than we do.
But there are also dangers lurking in the forests – microscopic dangers carried by tiny insects and other bugs. Ticks in particular are problematic. Certain ticks can carry a number of diseases that can make dogs sick, including Lyme disease (caused by Borrelia burgdorferi) and Rocky Mountain Spotted Fever (RMSF)(caused by Rickettsia rickettsii ). Both Lyme disease and RMSF are more common in certain areas where the tick species that carry them are present. You can NOT catch these diseases from your dog, but both you and your dog can be infected by the ticks that carry them. People can also be exposed to these pathogens by accidentally crushing an infected tick while trying to remove it from their dog. Ticks must be removed very carefully to ensure that the entire tick is removed, including the head and mouth pieces, without crushing it. If you're not sure how, contact your veterinarian. Also, the sooner the tick is removed, the less likely it is to transmit certain diseases, so be sure to check your dog thoroughly for ticks when you come back from a walk in the bush.
The Minnesota Department of Health recently reported that the number of cases of (human) Lyme disease increased in that state in 2007. This could be because of spreading tick populations, more people participating in activities in tick-inhabited areas, or increasing awareness and diagnosis of the disease by physicians.
If you and your canine companion will be spending time in some of the wilder and woodier parts of the great outdoors, talk to your veterinarian about what you can do to protect your dog. There are vaccines available for Lyme disease and the bacterial infection leptospirosis (which is also transmissible to people). Flea and tick preventatives are also very important, and many of today’s products are very effective. People should always wear insect repellent when camping or hiking in the woods. Visit the Health Canada website for safety tips on using personal insect repellents. All dogs should be vaccinated for rabies, whether they go camping in the backwoods or they’re house-bound city-slickers.
Rabies from a bat: tragic and preventable
A recent issue of CDC’s Morbidity and Mortality Weekly Report described a case of rabies in a person from Minnesota. This person died of rabies in 2007. Approximately one month before he became ill, he held a bat in his hands and felt a ‘pin-prick’. He didn’t see a wound or blood and assumed that he had not been bitten. Since neither he nor his family knew that this type of contact was actually considered rabies exposure, he did not seek medical attention. He died approximately 3 weeks after he developed rabies. Post-exposure rabies treatment would have almost certainly prevented his death. 
- Never handle a bat
- Assume all bats are rabid until proven otherwise
- Any contact with a bat is considered to be rabies exposure unless the bat has been tested and shown to be negative. All bat exposures should be reported to the appropriate public health authorities.
- Despite all the old stories, rabies exposure treatment is not horrible…it’s just a series of shots in the arm.
- Vaccinate your pets. You never know when they’ll encounter a bat…inside or out.
More information on rabies is available in our Resources area.
Horses and MRSA
Many people in the horse world have heard the hype about methicillin-resistant Staphylococcus aureus (MRSA) in horses. MRSA can cause infection in horses, just like it can in people, dogs, cats and many other animals. It’s usually what we call an “opportunistic” pathogen, meaning it usually takes advantage of a person or an animal that is already sick or injured, like someone who’s in the hospital and has just had surgery. And because MRSA is resistant to many different antibiotics, the infection can be difficult to treat. The big concern with MRSA in recent years is that infections are now sometimes occurring in people who aren’t sick, and who don’t have wounds or incisions, which is where MRSA usually likes to move in. It’s very important to find out from the start if an infection is being caused by MRSA, so that it can be prevented from spreading to other people and animals, and so that it can (if necessary) be treated with the right kind of antibiotic.
Horses are a bit of a special case when it comes to animals and MRSA. When researchers look at the DNA of MRSA from a dog or a cat, it usually turns out to be one of the common human MRSA strains (usually called a “clone”) from the same area. This means that the dog or cat probably picked up the MRSA from a person somewhere. When researchers look at the DNA of MRSA from horses, however, they often find a different clone, which seems to be more common in horses and people who work with horses than in people in general. A very similar situation has also been discovered in pigs. The worry is that this “horse MRSA clone” can survive in and be transmitted between horses better than the human MRSA clones. That means that in order to control MRSA, just controlling it in the people won't do the trick - we need to take steps to stop the spread of MRSA in horses specifically as well.
Here are some key points to help reduce the risk of your horse (and you!) getting MRSA:
- Always wash your hands with soap and water (or use an alcohol-based hand sanitizer) after handling a horse, and before handling another horse.
- This is especially important if you have touched a horse’s nose, or any cuts or wounds that the horse may have.
- Don’t go down the row of stalls in the barn and pet every horse on the nose! They love the attention, but this is a great way to spread MRSA if it’s there!
- New horses coming into the barn, or animals coming back from a hospital, should be kept separate from all the other animals and only dealt with after all the other horses, for 3-4 weeks.
- This is an important measure for controlling many infectious diseases, not just MRSA.
- If your horse has a cut that looks infected, cover it with a bandage of some kind and contact your veterinarian. Your veterinarian can culture the wound to determine if it is an MRSA infection.
Rabies vaccination...an Olympic event
In Beijing, 700 000 dogs have recently been vaccinated against rabies in order to combat the growing rabies epidemic there, and reduce the risks to people attending the 2008 Olympic games.
Unfortunately, rabies is common in China, with the number of cases increasing dramatically over the last decade. In 1996, there were 163 humans deaths due to rabies. This number increased to 3380 in 2007. Because of the seriousness of disease, the number of deaths and the low vaccination rate in dogs, a mandatory vaccination policy for dogs has been put in place. Free rabies vaccination is provided annually for each licensed dog. This could have a tremendous impact on the number of rabies cases, at least in certain regions. Control of rabies in rural areas is more problematic because of the lack of an organized registration and vaccination system for dogs in those areas. Perhaps not surprisingly, most cases of rabies occur in these rural regions.
So, the 2008 Beijing Olympics may have benefits for the dogs of China as well, or at least those in Beijing. This is certainly a preferred approach to the reports from last year of mass killing of thousands of dogs (including pets). Let's hope this progressive approach continues and the impact of this horrible disease decreases.
On a related note, the latest human death from rabies in Beijing was a person who was bitten by a stray dog two months before he became ill. He didn't seek medical attention at the time of the bite, he just cleaned the wound himself. If he had been treated for possible rabies exposure, he'd be alive today. While rabies is uncommon in many areas, no bite from an animal should be taken lightly. Rabies should always be considered and appropriate measures taken. More information about rabies is available in our Resources section.
HIV/AIDS and dogs
Here are a couple questions that I get periodically...
My dog licked someone with HIV/AIDS, and they had an open sore. Can my dog get HIV?
Can a dog that bites someone with HIV get infected?
If a dog bites someone with HIV then bites someone else right after, can it spread the virus?
The answers are no, no and it's very, very unlikely.
HIV (human immunodeficiency virus) does not infect dogs. Regardless of how a dog is exposed, it will not develop an infection. HIV is also a very fragile virus. It does not survive long in the environment and a dog's mouth is not a very hospitable location. It is theoretically possible that if a dog bit someone with HIV and then immediately bit someone else, it could transfer the virus, but this has not ever been identified and is very unlikely. In some countries, the source of all cases of HIV are investigated, and an animal bite has never been implicated as a potential cause.
Bottom line....don't worry about HIV and your pets.
Cats and avian influenza
The picture on the right is a Picasso painting entitled "Cat catching a bird". I often use this picture in presentations and ask "What if that bird was infected with avian flu?"
Avian flu is a tremendous concern at the moment. While it is not (currently) easily transmitted between people, bird-to-human infections have been reported in various countries. Mortality rates are very high, and the concern is that this strain could change to become easily transmitted between people, and lead to a pandemic (worldwide outbreak) not seen since the Spanish flu pandemic in the early 20th century. While birds and people are the focus, some attention has been paid to other species, such as cats.
Fatal avian flu developed in leopards and tigers in a zoo in Thailand during an avian flu outbreak. It was suspected that they ate infected chickens. Similarly, avian influenza in a pet cat was thought to have resulted from eating a dead pigeon (the pigeon presumably having died of avian flu). The potential role of cats in transmitting disease was highlighted by a study that reported that cats can become infected by eating infected birds, and can transmit avian flu to other cats.
While unproven, cats could theoretically play a role in transmitting this virus from birds to people. It's unlikely cats would be a major factor in a flu pandemic, but if such a situation were to arise, any possible source of transmission would need to be considered.
Should we worry about cats and avian flu right now? Worry....no. Be aware....yes. H5N1 avian influenza is not currently present in North America and it's hard to say if/when it will appear.
Should we think about cats when making plans for management of avian influenza if/when if reaches us? Absolutely. It's issues like this that get overlooked in outbreak planning.
Should I keep my cat inside? Yes. Outdoor cats are exposed to a large number of different infectious agents, including parasites and bacteria that can infect people. Outdoor cats can also get into fights, during which animals can transmit important diseases or cause nasty wounds. Also (obviously), an indoor cat isn't like to get hit by a cat...an important cause of premature death in cats.
Avian flu is just one more indication that our relationship with infectious diseases is much more complex than we've thought, and that broad (ecological) approaches to infectious disease control are required. We need to think about household pets when considering emerging infectious diseases because of the close and prolonged contact that millions of people have with their pets.
Hazardous hedgehogs
While most people that want a pet stick to the tried-and-true species, there are a huge number of different animals available. Some make good pets, some are relatively harmless but not suitable for most households and some are potentially dangerous. Hedgehogs probably fit into the latter 2 categories.
No...hedgehogs aren't sneaking out of their cages and attacking people as they sleep. Rather, they can carry a variety of microorganisms that can be transmitted to people. There have been a few reports describing infections associated with hedgehogs, particularly Salmonella and ringworm. An excellent report in the
journal Emerging Infectious Diseases highlighted the diseases hedgehogs have been shown to, or could, transmit to people. Hedgehogs don't have to be sick to be a source of infection.
Hedgehogs have been available for years, but they may be a fad pet at the moment. One breeder is quoted as saying “They are going up these last two months we actually have a waiting list about twenty people,” said Sarah Roberts a breeder in Mansfield. “That's never happened in the year’s of breeding we've done.”
While any pet could transmit infections to people, certain pets are higher risk. Overall, species that are rare or 'fad' pets may be of greater concern because we simply don't know much about them (i.e. what diseases they can transmit, how to reduce risks...).
These small creatures can probably be safe pets in some households, but are they really better than other species? You probably should not have a hedgehog if you or someone else in the household has a compromised immune system or if you have small children. If you do have a hedgehog, don't let it roam freely in the house and wash you hands after handling it.
My dog has MRSA... what do I do?
This is a question that I get on a regular basis. Methicillin-resistant Staphylococcus aureus (MRSA) is an antibiotic resistant bacterium that is a major cause of disease in people and is also a cause of disease in various animals species, including dogs and cats. It can cause a wide range of infections, from mild skin infections to rapidly fatal disease. Most MRSA infections in animals are treatable if managed properly and most are treated in the home (as opposed to requiring a stay at a vet clinic). Because of this, there are concerns about transmission of MRSA from infected pets to people in the household. Transmission of MRSA between people and pets (in both directions) definitely happens, although we don't really know how often this occurs.
If your pet has MRSA:
- Talk to your veterinarian about how to handle the infection
- Avoid contact with the infected site. If you have to touch it, use gloves and wash your hands immediately afterwards.
- Wash your hands regularly after contact with your pet
- Avoid contact with your pet's face...MRSA often lives in the nose, in addition to the site of infection
- Try to limit overall contact with your pet until the infection has resolved. Close, prolonged contact such as letting the pet sit on your lap or sleep on your bed should be avoided
- Follow your veterinarian's instructions closely. Always complete the full course of treatment, even if your pet looks better
- Talk to your physician if you have concerns about your health, particularly if you or someone in the household has a compromised immune system
Current recommendations are that there is no indication to test people or pets for MRSA carriage when there is an infected pet (or person) in the household. Testing might be reasonable in some circumstances where uncontrolled transmission of MRSA appears to be occurring in a household, but there does not seem to be a reason to test with single incidents of MRSA infection.
Studies are currently underway looking at transmission of MRSA in households where pets have an MRSA infection. Better information will likely be available in the future as a result of these studies.
More information on MRSA in pets will be available soon in our Resources section. Another good source of information is the Bella Moss Foundation, a charitable foundation dedicated to MRSA in animals.
Pet turtles and Salmonella...When will we learn?
A report in the Centers for Disease Control and Prevention (CDC)'s journal MMWR described a multistate outbreak of human salmonellosis caused by contact with pet turtles. Officials investigated 103 cases of disease cause by a specific type of the Salmonella bacterium. Contact with turtles was identified as an important risk factor for disease. Sixty-three percent (63%) of people infected by this strain of Salmonella reported contact with turtles in the week before getting sick, compared to only 4% of others. Many people that became ill reported having touched a turtle. Some even reported kissing a turtle (don't ask me why... I'm not making this up). Salmonella was cultured from turtles or their aquariums in some households. No fatalities were reported but some people were seriously ill and required hospitalization.
The association between turtles and Salmonella is nothing new. Upwards of 90% of healthy turtles may carry Salmonella bacteria. Antibiotic treatment is not effective at eliminating Salmonella carriage and there is no way to declare a turtle 'Salmonella-free'. People can become 
infected through direct contact with turtles or their environment. Sale of turtles with a shell length of less than 4 inches was banned in the US over 30 years ago. This was because of the strong association between turtles and salmonellosis, particularly in children. Small turtles are more likely to be handled by children and put in their mouths.This measure has been estimated to have prevented 100 000 infections every year, however it is clear that (illegal) small turtles can still be readily purchased from pet stores or other sources. Turtles were less than 4 inches long in 86% of cases in this report where turtle size was reported.
While turtles can be fascinating, they are definitely a high-risk pet. I used to have turtles but wouldn't consider it now that I have young children. There are much better and safer pets for children. They should be avoided by households with children or people whose immune systems may be compromised. People who have pet turtles need to take precautions to reduce the risk of infection, but it cannot be completely eliminated.
More information about turtles can be found in our Resources section.