Scott Weese
Scott Weese is an Associate Professor in the Department of Pathobiology at the University of Guelph, and Public Health and Zoonotic Disease microbiologist for the University's Centre for Public Health and Zoonoses. After graduating with a Doctor of Veterinary Medicine degree and spending time in private practice, he completed an large animal internal medicine residency and Doctor of Veterinary Science graduate program. He is board certified in internal medicine by the American College of Veterinary Internal Medicine and is Chief of Infection Control at the Ontario Veterinary College Teaching Hospital. He has an active research program focusing on infectious diseases, particularly those that can be transmitted between animals and people. He lives outside of Guelph, Ontario with his family and a collection of pets, including a dog, cat, fish and a herd of rare-breed sheep.
Campylobacter upsaliensis: an overlooked problem?
Campylobacter bacteria are important causes of disease in people. A variety of Campylobacter species exist, and these different species are quite variable in their ability to cause disease in people and animals. Campylobacter jejuni is one of the most common causes of diarrhea in people worldwide and is most commonly foodborne, however a few different studies have reported that having pets (especially pets with diarrhea) is a risk factor for Campylobacter jejuni infection.
Another Campylobacter species that may be of concern is Campylobacter upsaliensis. This species is primarily associated with dogs and cats, and a large percentage of healthy dogs and cats may be shedding this bacterium in their stool at any time. It doesn't seem to be a cause of disease in dogs and cats, but it may be an important and overlooked cause of disease in people. One study from the US reported that C. upsaliensis was the 2nd most common Campylobacter strain found in people with diarrhea (after C. jejuni). However, the true role of this species is unclear, partly because of common laboratory testing methods. Culture is the main method to diagnose infection with Campylobacter, but this bacterium can be difficult to grow. Usually, culture media for Campylobacter contain antibiotics to inhibit other, better growing, bacteria. Unfortunately, C. upsaliensis is often inhibited by these antibiotics, so it's possible to miss it. Therefore, we might be underestimating the role of this Campylobacter species in diarrhea. This is important to figure out because C. upsaliensis is strongly associated with dogs and cats, and it's important to determine what role pets play in human disease.
Avoiding Campylobacter infection involves some basic steps: avoid contact with feces, take care when handling diarrhea from pets, wash your hands regularly after handling pets and always after any contact with feces. Make sure your physician knows you have pets. In particular, if you have a pet with diarrhea or have recently acquired a new pet (especially a puppy or kitten), make sure Campylobacter infection is considered. Most infections are mild and go away on their own but some require specific treatment.
More information about Campylobacter can be found in our Resources section.
Image credit: CDC/ Dr. Patricia Fields, Dr. Collette Fitzgerald
More H1N1 cat cases
Perhaps not too surprisingly, more cats have been diagnosed with H1N1. Following the first reported case in Iowa, two more cases have been reported; one in Utah and one is Oregon. The Utah case apparently had typical flu-like disease. The cat from Oregon died of severe respiratory disease.
This doesn't really change anything. We know cats are susceptible, although not highly so considering the small number of cases despite large numbers of cats being exposed by their owners. H1N1 in cat is a human-associated disease, with cats getting infected from infected people. We still have no evidence that pets are a source of human infection. Despite that good general hygiene practices should be used around infected pets and people to reduce the risk of transmission in both directions.
Stray cats and H1N1 influenza
The topic of the potential for feral (stray) animals, particularly cats, to be sources of human influenza infection came up today. For feral animals to be a public health problem, the following sequence has to happen:
Feral animals need to be exposed to H1N1
- This is pretty unlikely. Influenza is spread through close contact, mainly through aerosols generated by an infectious person coughing, sneezing or breathing. Influenza only travels short distances in this manner. The likelihood of a feral animal being exposed to the H1N1 influenza virus is very low because it is rare for a feral animal to get that close to people. If there is close contact, it's probably very short term, and not high risk for exposure.
They need to become infected AND shed appreciable levels of virus
- Considering the number of infected people, how common pet cats are, and the fact that only one cat has been diagnosed with H1N1, the risk of actually transmitting the virus to a cat is very low even with close contact with an infected person. If tens of thousands of household pet cats have had close and prolonged exposure and only one infection has been diagnosed, this virus is pretty poorly transmissible to cats.
They need to be exposed to susceptible people
- As discussed above, there's not too much contact between stray cats and people. Close and prolonged contact is extremely rare. Influenza is only shed by infected individuals for a short period of time, unlike some other infections. So, the chance of an infected cat having close contact with a person during the relatively short infectious period is very low.
Each one of these events independently is very unlikely. When you combine them, it should be clear that the risks posed by feral cats are extremely low (probably about as close to zero as we get with infectious diseases).
A bigger concern might be someone infecting their indoor/outdoor cat, who would then infect a stray cat, which would then infect another indoor/outdoor cat, which could infect a family member. That's still a VERY unlikely situation - really it's nothing to worry about.
There are certainly public health issues with feral cats. H1N1 is not one of them.
How to remove a skunk from a pool
This morning, as my dog Meg and I went out to get the newspaper, she ran towards our pool fence, barking (pretty unusual for a dog that is afraid of chipmunks). I wondered what the issue was until I saw a black and white tail sticking out. The pool has been closed for the season and there was a skunk standing on the cover. The cover's about 1.5 feet below the deck and the skunk couldn't get out.
After going over various options, like putting things in for the skunk to climb out on (unsuccessful), getting a live trap (too lazy to go find one), scooping it up with the pool skimmer net (a matter of how badly I'd be sprayed, not whether I'd be sprayed), getting a wildlife removal person in (too cheap to get someone else to do it) or lacing food with a sedative, I came up with the following plan:
- Find a large garbage pail with a handle. Tie a long rope to one handle.
- Place the garbage pail on its side in the pool, with the handle tied to the rope on top.
- Lure the skunk into the pail (e.g. with food) or, as I did, herd it in using a LONG pole.
- When the skunk is inside, pull on the rope to tip the garbage pail back up.
- Cover the garbage pail. A plastic kiddie pool works well.
- Carefully but quickly lift the covered garbage pail out of the pool.
- RUN... upwind.
It worked for me... no guarantees however.
Family Salmonella outbreak from school reptile
Three Louisville, Kentucky children and their father recently contracted Salmonella from two lizards (green anoles) that the kids brought home from school. Two weeks after the lizards were brought home, the youngest child got sick. Then the other kids and the father got sick.
This outbreak highlights numerous problems:
Schools are not pet stores: Why is an exotic (and difficult to care for) pet that is a known Salmonella vector being sent home with students? Apparently, the school sent home a standard letter they use when students take home pets. (I assume sending animals home must be a very common event if the school has a standard form for it.) The letter provides "caretaking tips" but apparently mentions nothing about Salmonella and reptiles. The school has now modified the letter to include a "reminder to parents that good hygiene is imperative when dealing with any kind of living organism as a pet, so they need to make sure their kids wash their hands well after handling them or cleaning them out." That's better, but if they are sending home reptiles, they need a clear statement about the risk of Salmonella exposure. They need to be direct and highlight the greater risk associated with reptiles.
Lack of education before getting a pet: Too many pets die and too many people get sick because people don't take the responsible step of finding out about the animal before they adopt it as a pet. This is particularly true with exotic pets, and death of the pet is a common outcome. It doesn't take a lot of effort to find out basic information about reptile care, and information about the risk of salmonellosis should be easy to find.
Poor knowledge (or a poor attempt at damage control) by the school: The teacher "noted that other common pets, such as dogs, can also carry salmonella. Like lizards, they're perfectly safe as long as you practice proper handwashing when you handle them." Except for the fact that 0-1% of healthy dogs carry Salmonella while very high percentages of reptiles do, that tens of thousands of cases of reptile-associated salmonellosis occur every year, that contact with reptiles is a major risk factor for salmonellosis, and that the CDC (among other groups) recommends that children less than five years of age and other high-risk groups not have contact with reptiles. This type of statement is misleading. It's unfortunately either an indication of ignorance of the issues or an attempt to cover their butts and not take their share of the responsibility for what happened. Certain reptiles can be good pets in certain situations, but are clearly inappropriate in others.
The "it's never happened before so it must be safe" fallacy: The school's disappointing response was that they've been using lizards in classrooms for years and no one has gotten sick. Well, their luck just ran out. Just because I could drive around without a seatbelt and not get hurt doesn't mean not using a seatbelt is a perfectly safe plan. Risky behaviours tend to catch up with you eventually.
The "it didn't happen here so it's not our fault" excuse: School officials said teachers are well-trained on the proper way to prevent students from getting Salmonella, but that's pretty debatable since three kids got sick because of their actions (i.e. sending the reptiles to the children's home). The infections may not have originated in the school but the school was still the source of the problem.
Poor hygiene associated with reptile contact: The father admitted that they didn't wash their hands regularly after handling the lizards.
There's little excuse for sending reptiles home with kids. Reptiles require specialized care and commitment, and many (many!) die each year from inappropriate care. The last thing we need is to make it easier for people to obtain them without much forethought. Reptile-associated salmonellosis is a serious problem, especially in kids. Serious, including fatal, infections can occur. Schools need to realize the liability they might assume by sending these animals into households, especially with inadequate scrutiny and education. Reptiles should not be kept in households with kids less than five years of age, pregnant women, elderly individuals or immunocompromised individuals. I doubt they asked whether any such people lived in the household before sending the reptiles home.
H1N1, cats and the potential for mutation
I've spent a lot of time talking to the press this week about H1N1 and pets. One question that has come up repeatedly involves concern about the potential for this virus to mutate because of its presence in pets. This largely relates to the general knowledge that pigs are potentially important "mixing vessels" for influenza viruses.
H1N1 infection of cats carries almost no risk of a significant mutation. For this to happen, the animal must be infected with two different influenza viruses, and those viruses must recombine so that a new virus containing parts of each of the parent viruses is produced. This virus must then be able to infect a new host and be transmitted. Pigs are a concern because they can be infected by various influenza viruses (from humans and birds, as well as swine-origin viruses), and they tend to live with many other pigs so that the transmission cycle can be started. This isn't the case with cats.
Cats don't have their own influenza virus that is in circulation. Therefore, it's very unlikely that a cat exposed to H1N1 already has a different influenza virus in its system. Even if a cat was infected with a different flu virus (which is exceedingly unlikely) and this virus recombined with H1N1 (which is unlikely even if the two viruses were present), your average cat doesn't have much contact with different individuals, human or animal, and it's quite possible that the virus would just die-out in that animal.
While we don't want to ignore some of the issues regarding H1N1 in pets, such as the potential for pet illness and the unproven possibility that they could transmit H1N1 to other people, we need to keep the concerns in perspective. The risk that pets pose to people is much lower than the already very low risk that people pose to pets, in terms of H1N1 influenza.
Human vaccinia infection from rabies bait exposure
Rabies baiting is a highly effective way to reduce rabies in wildlife populations. As we've discussed before, in Ontario this involves air-dropping edible rabies vaccine. These baits are dropped in key rural areas, but there is the potential for curious people to come into contact with the vaccine if they handle baits that they come across. It is recommended that people avoid contact with the baits and wash their hands if they do come into contact with one, because the baits contain a live virus. They do NOT contain live rabies virus. Rather, they contain a vaccinia virus that has been manufactured to produce immunity to rabies virus. The risk of human infection is low, but as we constantly get reminded with infectious diseases, low doesn't mean zero.
Today's MMWR reported a case of human vaccinia infection associated with a rabies bait. In August, a 35-year-old Pennsylvania woman was picking berries and her dog and found a rabies bait. The dog punctured the bait packaging and the woman subsequently handled the bait. It took around 30 minutes for the woman to reach somewhere she could wash her hands, which she then did. This person had a few factors that put her at higher risk of developing an infection, including some skin lesions on her hands from berry thorns, and she was on multiple immunosuppressive drugs.
The day after exposure, her doctor took blood samples for rabies and vaccinia virus antibodies and examined her hands. Skin lesions (papules, i.e. little bumps) developed three days later. These lesions were tested and vaccinia virus was found in them. The skin lesions progressed and she was hospitalized a couple of days later. She was treated with antibodies against vaccinia virus because of the progression of disease and her compromised immune system. She went on to develop muscle aches, headache and a swollen lymph node. She was treated with more antibodies and an experimental antiviral drug. She ultimately responded to treatment and was discharged from the hospital on day 19.
This is the second reported human infection associated with a rabies bait. Considering the millions of baits that have been dropped and the presumably relatively large number of people that have had some contact with the baits, the overall risk of disease is still very low. This person was at high risk because of her immunocompromised status, and it's likely that an otherwise healthy person would not have developed an infection like she did. The big problem here was her contact with the bait. She did everything right after that: washed her hands as soon as she could, called the Department of Health, went to her physician and ensured that testing was done, but she still got sick.
Avoid rabies baits. The risks are low but why take any risk? People that have compromised immune systems or skin diseases should take particular care. If you've been exposed to a rabies bait, wash your hands ASAP and contact the local health authorities to determine if anything else should be done.
Image from: http://www.mnr.gov.on.ca/en/Business/Rabies/2ColumnSubPage/275904.html
How to diagnosis influenza in pets
One of the common questions accompanying the onslaught of calls I've taken today is "How do you diagnose influenza in pets?"
Clinical signs, such as sneezing, coughing, fever and lethargy, are not useful for diagnosis. Influenza can produce highly variable disease, ranging from almost none to very severe - so you can't look at an animal and say it has influenza just based on the clinical signs. We don't know much about H1N1 influenza in different animal species (including pets), but this type of influenza can probably cause a wide range of disease in animals as well (at least in those it can infect).
The presence of someone in the household with influenza should get you thinking about flu in a sick pet, but it is far from diagnostic. Many, many people have influenza, but very few pets do. There are many other diseases that can produce signs similar to influenza in pets. The health of people in the household is an important thing to know, but we can't jump to conclusions based on the household history alone.
Laboratory testing is required for the diagnosis of influenza, and there are a few options:
- PCR testing of nasopharyngeal (throat) or nasal swabs, or fluid collected from the trachea: This molecular test detects influenza virus RNA. This is the fastest test and it is most sensitive when samples are taken early in disease. This is the main option for diagnosis at this time.
- Serology: This involves testing blood for antibodies against influenza. Two samples are taken 10-14 days apart. If the antibody level rises 4-fold or greater, that is indicative of influenza infection. This is considered the most reliable method of diagnosis of influenza in many species but takes time. It is not currently a viable option for pets because tests for pets are not available.
- Virus isolation from nasopharyngeal or nasal swabs, or tracheal fluid: Samples are inoculated into eggs to try to grow the virus. This can take quite a while and isolation of the virus can be difficult. This is a method used by specialized labs with laboratory containment conditions appropriate for this virus and may not be readily available.
H1N1 in a cat
H1N1 influenza has been confirmed in a cat in Iowa. The cat had "influenza-like illness" and was tested, with H1N1 being confirmed today. Two of three people in the house were also sick, but they became ill before the cat, and were presumably the source of infection for the cat. There's no evidence that the cat has infected anyone.
This doesn't really change anything that we've been recommending regarding H1N1 and pets. H1N1 infection is pets is rare but has been diagnosed in ferrets, and now in a cat. Considering the large number of infected people and the presumably large number of exposed pets, the risk of transmission to pets appears to be extremely low. Low doesn't mean no, however, and taking basic precautions is still wise.
Basically, remember that your pets are part of the household - microbiologically as well as socially. If you are doing something to reduce the risk of transmission of infection to people in the household, act the same way around your pets. Reduce contact with pets if you are sick. Avoid being around them when you are coughing. Wash your hands frequently. Avoid contact with their faces. If your pet gets sick after you've had H1N1 (or any other infection) make sure your veterinarian is aware of it.
Image source: icanhascheezburger.com
'Registered' service dog scam
I've written a few times in the past about the need for better definitions and guidelines for service dogs. Service animals are incredibly beneficial for some people, but there is great potential for abuse of the "service animal" designation by people who don't really need a service animal and/or are using completely untrained and sometimes inappropriate animals.
An example of such unscrupulous behaviour is RegisteredServiceDogs.com. At this site, you can enter your pet's name and your information, and get a form for your physician to sign requesting the dog be authorized as a service animal - but there is no such process, and this company has absolutely no authorizing power! Additionally, there's a place for a vet to sign affirming that the dog being "registered" has had all shots required by the state and that, to the best of the vet's knowledge, it will not be a threat to the general public. There is no mention about whether the dog is healthy, is well-trained, is specially trained as a service animal, has undergone any real scrutiny to determine whether it could be a "threat to the general public", or anything else that should be a requirement for a true service animal. In other words, this company does absolutely nothing to ensure that the animal is an appropriate service animal. For their overwhelming effort of providing you with a form to fill out, they charge $49.95 to send you a worthless card saying your dog is a "registered service animal".
Anyone who has a real service animal has no use for a card such as this. If they run into someone who inappropriately tries to restrict their access, they're better off with information from the agency that trained the animal or, in the US, a copy of highlights of the ADA, since restriction of service animals is illegal.
If this company was really in it to help the cause of service dogs, it would have some standard criteria to ensure that the animals it certifies as service dogs are really service dogs. Otherwise, it's a money-grab to provide a useless card to people with true service animals, and a way to help people who just want to take their pets with them to places where they are banned. None of this helps the cause of true service dogs. It is a disgrace.
Anyone with a service dog that has questions or concerns about access should contact the agency that trained their dog or another reputable (non-profit) source of information such as Delta Society.
Image source: www.guidedogsofamerica.org
