Check out the new information sheets about Clostridium difficile now available on the Resources page!
Exposure to animal blood
Periodically, pet owners may be exposed to blood from a pet. This can range from exposure to small amounts of blood through minor injuries like cut foot pads or broken toenails, to large amounts of blood following severe trauma.
In people, there are detailed protocols for avoiding blood exposure in healthcare situations, and protocols for managing people exposed to human blood in hospitals and in the community. This is mainly driven by concerns about HIV and hepatitis viruses that can be transmitted by contact with blood. But these viruses are not present in animals, and the risks of transmission of disease from pets to people through blood are very low. Even contact with blood from a rabid animal is not considered rabies exposure, because the virus is found in the saliva, not the blood. This has led to a rather cavalier approach towards blood exposure in veterinary medicine, which is understandable but not ideal. New infectious diseases continue to emerge in animals and people, and eventually there is likely to be one that can be transmitted between species by blood. Therefore, it is prudent to try to reduce exposure to animal blood when possible, but without getting overly concerned (or paranoid).
- Direct contact with animal blood should be avoided whenever possible.
- In particular, avoid getting animal blood on any cuts, scrapes or other broken skin, and avoid getting the blood in your mouth, nose or eyes.
- If you do get animal blood on your skin, wash it off as soon as possible.
- While it is extremely unlikely for a person to get sick from touching animal blood, make sure you tell your physician about the incident if you do become ill.
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.
Do you know where 'that doggy in the window' came from?
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Nearly 700 dogs were seized in the largest puppy mill raid ever in Tennessee. Puppy mills are large scale breeding operations that produce large numbers of puppies under questionable to horrible conditions. They typically raise dogs under intensive conditions, such as in cages in barns. There may be little attention to the quality of parents, with the goal being production of a large number of puppies, not production of healthy, happy and safe household pets. These conditions lead to increased risk of health problems, carriage of infectious diseases that can be transmitted to people and behavioural issues related to lack of proper care, inbreeding, poor veterinary care, lack of socialization with people and little attention to breeding appropriate parents. The high rates of infectious diseases can lead to excessive and inappropriate use of drugs like antibiotics and antivirals. Some puppies receive multiple rounds of drugs while passing through puppy mills and pet stores. Overuse of antibiotics and important antiviral drugs like Tamiflu is a major concern.
Unfortunately, puppy mills (and smaller poor-quality breeding operations) are widespread, especially in some US states. Puppies from these operations can be sent across North America and sold through newspaper ads, internet ads and pet stores.
Puppy mills exist because there is a market for the puppies. I've never understood why people often spend incredibly large amounts of money for dogs of questionable background, marginal health and potentially raised in inhumane conditions. Why buy a puppy that might have originated from a puppy mill when you can get a puppy (probably healthier) from a humane society or reputable breeder? Great dogs are awaiting adoption at humane societies. Otherwise, get to know the breeder. Good breeders make sure that their dog is appropriate for you, and you are appropriate for the dog. Places offering multiple breeds, that always have puppies available upon demand and don't ask a lot of questions about potential buyers are a concern and could indicate that the puppies are being raised in puppy mill-like conditions.
Dog bites cost millions
A recent report by the Insurance Information Institute stated that 1/3 of US homeowner insurance
liability claims that were paid in 2007 were due to dog bites. This represented a cost of over $356 million! The average cost per claim was an astounding $24 511.
This is just one more piece of evidence indicating the importance of dog bite prevention. The $356 million cost is just insurance claims. Not all bites are associated with insurance claims but can still be associated with financial costs, in addition to the obvious pain and emotional costs. There were ~14 500 insurance claims in 2007, but it is estimated that 4.7 million people are bitten by dogs in the US each year, with 800 000 people requiring medical care.
In the US, dog owners are liable for injuries caused by their pets in the following circumstances:
- if the owner knew the dog had a tendency to bite
- if a state statute makes the owner liable, whether or not the owner knew the dog had a tendency to bite
- if the injury was caused by carelessness on the part of the owner
It is important that everyone, pet owners and non-pet owners alike, know how to reduce the risk of being bitten by a dog. More information on bites can be found in the bites archives or in the dog information sheets in the Resources section.
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:
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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.
FDA Requests Seizure of Animal Food Products at PETCO Distribution Center
The US Food and Drug Agency (FDA) has issued a warning about pet food produced by PETCO in the US and sold at PETCO stores in Alabama, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Michigan, Minnesota, Missouri, Nebraska, Ohio, Oklahoma, Tennessee, Texas, and Wisconsin. The food production facility was inspected in April and had a serious bird and rodent infestation. The problems had not been corrected by the next visit so the FDA seized the food. They are concerned that the poor hygienic conditions in the facility could put pets at risk from eating the food, or people at risk from handling the products. No illnesses in people or pets have been reported, but au
thorities are urging people to report any possible cases. They are also recommending that people wash their hands thoroughly if they have had contact with these products (including packaging), and that they wash any surfaces that have come into contact with these products (including packaging). Presumably, people should contact the store about a refund (I'm not sure I'd want a replacement from a plant that was shut down for repeated serious hygienic breaches).
Any potential illnesses associated with these products should be reported promptly to the FDA's consumer complaints coordinators.
There is no indication any of these products were sold in Canada.
Pet store sued over bird owner death
Once again, a pet store is being sued following a death related to a pet sold at the store. Earlier, we
reported a pet store being sued by a woman whose husband died of lymphocytic choriomeningitis virus. Now, a pet store is being sued after a man died of psittacosis. This disease is caused by Chlamydophila psittaci, a bacterium that is most commonly found in psittacine birds (parrot family). It can cause disease in birds but can also be carried by healthy birds. The family had purchased a cockatiel prior to the man's illness, although details about the timing of disease, the bird's health and whether the bird was identified as carrying Chlamydophila psittaci aren't clear.
Typically, psittacosis causes flu-like disease and is easily treated, if diagnosed properly, however more severe disease can develop. Infected birds can shed the bacterium through feces and nasal secretions. People usually become infected by inhaling aerosolized bacteria from dried feces or nasal secretion.
Psittacosis is an uncommon disease. Only 125 human cases were reported to the CDC in the US between 2000 and 2006, however many more cases probably occurred. The risk of acquiring psittacosis from a pet bird is very low.
- Bird owners should make sure that their physician is aware that they have contact with birds. Psittacosis should be considered in people with flu-like disease that have bird contact.
- Do not buy birds that look unhealthy (lethargy, nasal or eye discharge, ruffled feathers...).
- If you have other birds, isolate new birds for 30 days before allowing them to have contact with existing birds.
- Reduce aerosolization of materials when cleaning cages. Lightly wetting cage paper will reduce the risk of aerosolization.
- Wash your hands after handling birds or cleaning their cage.
Dog flu in Chicago
The Chicago Tribune is reporting canine influenza in dogs in the Chicago area. These are the first reported cases oin Illinois. Canine influenza has now been reported in 27 American states. It has also been previously identified in the UK.
Here are some canine flu facts:
- Canine influenza originated from an equine influenza virus.
Canine influenza can cause a wide range of clinical signs, ranging from mild illness (cough, fever, decreased appetite and activity) to very severe (and potentially fatal) pneumonia. - Dogs that have frequent contact with other dogs (e.g. in kennels or parks) or dogs in shelters are at higher risk of catching the virus.
- About 80% of dogs that are exposed to this virus will get sick.
- Most affected dogs recover fully.
- Canine influenza cannot be diagnosed just by looking at the dog. Various other bacteria and viruses can cause similar disease.
- Because the disease is caused by a virus, it can NOT be treated directly with antibiotics (just like influenza in people!)
- There is no vaccine for canine influenza.
- Canine influenza is not transmissible to people.
- Try to keep your dog away from any dogs that looks ill, particularly those that are coughing.
- If your dog starts coughing or looks otherwise sick, you should take your dog to the vet, especially if your dog has been in a kennel, shelter or in contact with another sick dog.
More information about control of canine influenza can be found on the American Veterinary Medical Association Public Health Information website.
To our knowledge, there are still no reported cases of canine influenza in Canada. However, it seems inevitable that the virus will eventually make its way north of the US border, considering the number of US states that are now affected.
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.
Molly the peeing lab
Molly is a 1-year-old Labrador Retriever (not mine!) that has a peeing problem. She often urinates in the house when she's excited, which raises the question about how to clean up such accidents.
In general, urine is sterile and is not a risk for disease transmission. Simply removing urine from the area should therefore be adequate. However, urinary tract infections can happen, and some of the bacteria that cause these infections could be transmitted to people, although the risk is likely extremely low. The risk is probably greatest in pets that develop repeated urinary tract infections because of underlying diseases such as diabetes. Another concern is leptospirosis, a bacterial infection that can cause kidney failure and that can be transmitted to people. More information on leptospirosis is available on the Worms & Germs Resources page.
In most situations, indoor urination is more of an annoyance than a real health risk. If a pet suddenly starts urinating in the house, it should be examined by a vet to look for any of the many health or behavioural problems that can cause this. This includes testing for a urinary tract infection. If an infection is present, or a pet has suddenly started urinating in the house for an unknown reason, it is prudent to be more careful about cleaning it up than one might be when dealing with housetraining accidents in puppies, or with dogs with certain chronic urination problems not related to infection.
Urine should be removed with disposable paper towels, which are promptly discarded. The area should also be disinfected, if possible. Smooth surfaces (e.g. linoleum, tile, hardwood) can be wiped with any appropriate household disinfectant. Carpets are harder (if not impossible) to disinfect. Always wash your hands after cleaning up any accidents.
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.
Psittacosis
The National Association of State Public Health Veterinarians (NASPHV) has recently released a comprehensive document about psittacosis. This is a disease of people caused by the bacterium Chlamydophila psittaci (formerly known as Chlamydia psittaci). Psittacosis usually causes flu-like disease but can cause severe pneumonia and other problems. Chlamydophila psittaci is most commonly carried by healthy psittacine birds (those in parrot family) but can also be carried by non-psittacine birds including pigeons and doves. It is an uncommon disease in people but sporadic cases and outbreaks do occur. While treatable, psittacosis is often overlooked in the early stages of illness if the physician does not know the patient has had contact with birds. People that own or have contact with birds should know about psittacosis, and the NASPHV document is an excellent resource.
This disease is another good example why people should make sure their physician knows what types of animals they own or have contact with.
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.
Clostridium difficile in dogs
Clostridium difficile is a bacterium that is an important cause of disease in people and has been getting a lot of press lately in this area. Associated with that has been a lot of questions about C. difficile in dogs. Here are some facts to ponder:
- C. difficile is thought to be a cause of diarrhea in dogs in the general population, although its true role in disease is still unclear. C. difficile infection in dogs may cause mild to moderate diarrhea that is treatable.
- Some (<5%) healthy dogs can carry C. difficile in their intestinal tract. They may never have a problem with it.
- Dogs that visit human hospitals have much higher rates of C. difficile carriage, but we currently don't have any evidence that they are at higher risk for disease. They probably ingest the bacterium from the hospital environment and patients' hands.
- We are highly suspicious that C. difficile can be transmitted between people and pets (in both directions), but pets are probably not a major source of infection for people.
- Don't use antibiotics unless they are actually required. This goes for people and pets.
- Wash your hands regularly.
- Avoid contact with dog stool, especially diarrhea.
- Enjoy your pet. There is always a risk of disease transmission but the risk of getting C. difficile from your pet is not something to stay up worrying about.
Indoor cats and vitamin D
We've made statements supporting keeping cats indoors in different posts, and on our Cats fact sheets in the Resources section. There were many reasons for this, including keeping your cat safe from predators and other cats, and reducing the risk of infectious disease exposure. Outdoor cats are much more likely to pick up various infectious diseases, some of which can be harmful to the cat and some of which can be spread to people. This is a particular concern in households with people that are at increased risk of infection or where infections might result in more serious disease (i.e infants, elderly, people with compromised immune systems, pregnant women).
Recently, a comment was submitted in response to one of those posts. It questioned whether indoor cats would get enough vitamin D. It's a logical question and a good example of the differences between animal species. In people and some animal species, sunlight (UV light) exposure is important for production of vitamin D. Vitamin D is an essential vitamin and numerous health problems have been associated with vitamin D deficiency. However, cats are very poor at producing vitamin D in response to sunlight exposure. They get their vitamin D from their food. In the wild, cats get it from the prey they hunt. Pet cats get it from good quality pet foods that are supplemented with vitamin D.
Cats do not benefit from sunlight, from a vitamin D standpoint, so concerns over vitamin D should not be a factor in deciding whether your cat goes outside or not.
Dog bite prevention week
It's National Dog Bite Prevention Week in the US. This is a good time for dog owners, parents and the general public to think about ways to avoid bites from dogs and other animals. Dog bites are very common; many cause only minor injury, but some can even be fatal. It is estimated that 4.7 million people in the US are bitten by dogs each year, and that 800 000 of these people require medical attention for their dog bites, and that 10-34 people die as a result of their wounds. In the majority of cases, people are bitten by a dog they know, either their own or a neighbour's dog, but strays and other dogs may also bite. Not owning a dog, therefore, does not make someone immune to the risks. Someone who does not know how to interact with a dog could be at higher risk of being bitten when they do encounter a dog. It is very important that children be taught when they should not and when they may approach a dog, and how to safely interact with a dog to reduce the risk of being bitten. It is also critical for people to know what to do if they are bitten. 
Some key points to teach children:
- Never approach a strange dog
- Be careful and quite when approaching a dog - never make sudden movements or loud noises
- Do not play with a dog without adult permission and supervision
- Never disturb a dog that is eating, sleeping or taking care of puppies
- Never take something out of the mouth of a dog
- Avoid direct eye contact with strange or aggressive dogs
- "Be a tree": If confronted by a strange or aggressive dog, remain still and quiet
- If knocked over by a dog, curl into a ball and remain still
- Tell any adult about any bite. Try to remember as many details as possible about a dog that bites so that the owner can be found and the rabies vaccination status of the dog verified
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.
Fido fights allergies
Although allergies are not an infectious disease that can be transmitted from animals to people, many a household is declared a “pet-free zone” because one or more of the people who live there is allergic to our furry friends. But for many others, the itchy, watery eyes, sniffles and constant need for antihistamines are a small price to pay for the companionship of their beloved pets.
It's estimated that as many as 15% of people are allergic to pets such as dogs and cats. But a new study from Germany has come out that shows that having Fido around when you're very young may actually help decrease the likelihood that you'll develop allergies later on. In the study, infants who lived in a house with a dog were less likely to develop allergies to things in the air such as pollen and dust by the time they were six years old, compared to children that did not live with a dog. This may be because having a dog around exposes an infant to certain allergens that help “train” the immune system from an early age not to over-react and therefore cause allergies. There was no significant difference in the likelihood that a child would develop allergies specifically to dogs between the two groups.
The American Kennel Club lists several dog breeds that tend to cause fewer problems for people with allergies. But in truth there is no such thing as an non-allergenic dog (or cat) – it’s a matter of degree, and also depends very much on an individual person’s immune system, and your symptoms may also depend on how many other allergens you are exposed to at the same time. Most adults cannot be “cured” or their allergies, but if you have allergies and suspect that your pet may be contributing to them, talk to your doctor about things you can do to try to reduce your symptoms to a more liveable level.
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.
Prescription pets
It’s not “take 2 doses of Fido and call me in the morning”, but contact with pets has been shown to be beneficial to people in hospitals and nursing homes. However, concerns have been raised about whether Fido could be spreading more than good will; from Salmonella and ringworm to superbugs like methicillin-resistant Staphylococcus aureus (MRSA).
Recently, new international guidelines for these programs were published in the American Journal of Infection Control. A joint effort of physicians, infection control personnel, veterinarians and visitation program representatives, these guidelines provide comprehensive recommendations on how to run these programs and reduce the risk of disease transmission. Among the areas covered are appropriate animals, health care for visitation animals, appropriate human-animal interaction and the roles of visitation programs, pet owners and hospitals. “The goal of these guidelines is to keep these highly beneficial animal-assisted interventions safe for all involved. That means protecting not only the patients but the pets, as well as other people and animals the pets may subsequently interact with”, said lead author Dr. Sandi Lefebvre.