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.
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.
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.
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.
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.
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
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
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.
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 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.
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.
UK Chief Vet says no pets in bed
The UK’s Chief Veterinary Officer Fred Landeg recently declared that pets should not be allowed to sleep in peoples’ beds or even be allowed in the bedroom. The reasoning behind this recommendation was the potential for transmission of bacteria such as Salmonella and Campylobacter. This was in response to a publication in the Veterinary Record describing animal-human interactions in households in the UK. It reported that 20% of participants let their dogs sleep in the bedroom and 14% let their dogs sleep in their bed.
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While it is certainly true that any healthy animal (and person) can carry infectious diseases, and that prudence is reasonable, there is simply no evidence supporting this recommendation for the average household. Any contact with pets carries a very slight risk of disease transmission, just like any contact between people. There is currently no evidence, however, that sleeping with a pet in the bed increases the risk of disease. For your average pet and average household, this is probably exceedingly low risk and the recommendation is very difficult to justify. It is a reasonable recommendation when the pet is known to be carrying something that is transmissible to people (such as MRSA or Salmonella) or when a person has a compromised immune system. Banning pets from the bedroom completely doesn’t make any sense.
Personally, my dog is not allowed in my bed. However, that’s not because of disease concerns, it’s because she’s a large dog that snores and certainly can be a bed-hog. I have no problems with my cat on the bed. Life is never completely free of risk. If you enjoy having your pet in the bed, and you’re both healthy, I don’t see a reason to stop.
Not-so-likable licks
Sometimes when you fall and scrape your knee, or cut your hand, your favourite furry friend, in an act of unhindered devotion, will do to you what they would do to their own cuts and scrapes – they will try to lick it clean. The story that is often cited is the one about dogs and cats having enzymes in their saliva that help clean the wound. While it can’t be denied that there are various enzymes in the slobber, when you consider what else is in your little friend’s mouth, you’d be better to pass on their touching offer to help you clean up your cuts.
First of all, think about where that mouth has been, and what’s been in it! Does your cat hunt mice and birds around your house? Does your dog have a habit of eating unidentifiable bits of garbage or poop when out on walks? Or maybe your dog, like so many, enjoys a snack from the cat’s litter box every once in a while. You probably want to keep things like garbage and poop out of your cuts, and if your pet’s mouth has been there, it shouldn’t be near your wounds either.
Even dogs and cats that don’t have any distasteful eating habits have millions of bacteria of many different kinds in their mouths. Most of the time the bacteria don’t cause a problem, and the “good” bacteria help to keep the “bad” bacteria in check. But if the “bad” bacteria are put somewhere the body’s defense systems have already been breached – like an area of broken skin – those same bacteria suddenly have a prime opportunity to move in and start multiplying in their new home. Some bacteria like Pasteurella multocida can cause very serious infections in situations like this. This species of bacteria is one of the primary culprits in bite wound infections, which are especially common with cat bites.
So why do animals lick their wounds in nature? Well, “dirty” is in fact a relative term. An animal can use its tongue to get the worst of the dirt and debris out of a wound, and the wound will be cleaner. But compared to how clean you can make a cut by even just washing it with a lot of water and some soap, and maybe a little disinfectant, a lick from a cat or a dog is counterproductive to say the least. So the next time you have a boo-boo that Fifi or Fido wants to kiss better, say thanks, but no thanks.
Why should I vaccinate Fluffy, he's an indoor cat? (aka Why I'm glad I vaccinated Finnegan, my indoor cat)
Picture this. I’m driving home from the airport and get a call from my wife who’s locked in the bedroom with our kids because a bat is flying around the house. It’s not necessarily a big deal, except for the fact I thought I might have seen a bat in the house a couple days earlier, and a bat in a house with access to sleeping people = rabies exposure! I’ll save you the long but somewhat funny saga, and just say I eventually caught the bat. Our sigh of relief was short-lived, however, because it came back rabies positive. That meant we all needed rabies post-exposure prophylaxis (2 shots for Heather and I who have been vaccinated, but 6 shots for each of the kids). We also have a dog and cat, and they had to be considered exposed as well (the cat almost caught the bat). The cat, Finnegan, is an indoor cat but
was vaccinated. The repercussions on the animals were much less than on us. However, if they had not been vaccinated, we would have had a problem.
Protocols for rabies exposure in non-vaccinated animals vary between jurisdictions, but long quarantines are the norm, and euthanasia often is chosen.
The take home message is, even with indoor-only animals….if you care about yourself, your family and your pets, vaccinate your pets against rabies. In most places it’s the law. It’s also good sense.
Information Sheets for Pet Owners
INFORMATION SHEETS specifically for VETERINARIANS and for KIDS are also available on the Worms & Germs RESOURCES page!
Click on the highlighted topics below for information sheets. Topics that are not highlighted are in development and coming soon. Sheets for other animal species and diseases are also under development and will be added when they are available. 
| Animals | Diseases | Other |
| Dogs | Rabies | Litter Boxes |
| Cats | Giardia | Sandboxes |
| Turtles | Toxoplasma | Cat Bites |
| Hamsters | Leptospira | |
| Clostridium difficile | ||
| Cryptosporidium | ||
| MRSA | ||
| Campylobacter | ||
| Salmonella | ||
Please Remember:
- Your veterinarian and physician are your ultimate resource for information about the health of your pets or your family.
- Information provided here is accurate to the best of our knowledge, but infectious diseases can be unpredictable and these sheets are for general information purposes only.
- There can be great variation in disease risks in different geographic areas. The information provided was developed for Ontario, Canada, but most of the information is relevant for other regions as well.