Worms and Germs Blog : Animal Health & Diseases : University of Guelph : Ontario Veterinary College : Zoonotic Diseases : Guelph, Hamilton, Ontario

I periodically get questions about whether rabies vaccination is really required or if it's just a good idea. There's not a straight answer because legal requirements vary by region. In Ontario, Regulation 567 of the Protection and Promotion Act states that all dogs and cats three months of age or older that reside in specified areas of the province must be vaccinated. Further, animals must be revaccinated by the date specified on the certificate of immunization. Basically, this means that all dogs and cats must be vaccinated and they must be up-to-date on the vaccination, based on the type of vaccine that was used.

Even if vaccination isn't legally required, if rabies is in an area, it's a good idea because:

• If a pet gets rabies, it will die.
• If a pet gets rabies, owners or other people in contact with it may need post-exposure treatment.
• If a pet gets rabies, it could infect people with this almost invariably fatal disease.
• If an unvaccinated pet gets exposed to rabies, it will need a strict 6-month quarantine or euthanasia. (Euthanasia is common in these situations.) If the pet was vaccinated, all it needs is a 45 day home observation.

Rabies vaccination of pets is easy, cheap and safe, and often required by law.

Image source: http://amcny.wordpress.com

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I had an advice call the other day about two cats that were found with a dead bat. One cat was vaccinated against something (not sure what or when) while the other cat was unvaccinated. This is a situation that, if managed properly, can be very minor, but if handled improperly, can be a major problem, even resulting in death of the animals.

Bats are notorious rabies vectors. The odds of this bat carrying rabies are probably low, but they are not zero and a rabid bat is going to be more easily caught than a healthy bat. Any contact of an animal with wildlife in areas where rabies is present is considered a possible rabies exposure unless proven otherwise. The only way to do this is to have the bat tested.

If the bat is tested and is negative, then everything's fine. If it's positive, then the vaccinated cat would need a rabies booster vaccine and would have to be observed at home for 45 days. The unvaccinated cat would need a strict six month quarantine or would have to be euthanized. So, it's clear that the rabies status of the bat and the vaccination status of the cats are crucial.

Here's what to do in a case like this:

• Get the bat. The bat needs to be tested so you have to maintain control of it. Don't let the cat eat it or run off with it. Don't leave it outside where a person or animal could walk off with it. Put it in a bag or container, without having direct contact with it (e.g. use gloves or a scoop to pick it up). Be very careful if it's not completely obvious that the bat is dead, because an injured bat might look dead but still be able to bite.
• Submit the bat for testing. In Canada, that's done through the Canadian Food Inspection Agency. Make sure they know that an animal has been exposed to the bat. They would not likely test the bat if there was no exposure. They can be contacted directly or through your veterinarian. There is no charge for testing.
• Find out the vaccination status of the cat(s). You need to know when the last rabies vaccine was given and what type of vaccine was used (1 year or 3 year). You need to be able to demonstrate that the pet is current on its rabies vaccination if the bat is positive and you want to avoid the long quarantine.
• Figure out why/how/where the cat(s) caught the bat, and whether that can be avoided in the future.

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Trap/neuter/release (TNR) programs involve trapping feral (stray) cats, then spaying or neutering and vaccinating them. Some cats are adopted, while the majority are released. The goal is to reduce the feral cat population by limiting the number of breeding animals, and to increase overall vaccine coverage in order to reduce illness and deaths. One such TNR program has come under fire in a Texas town.

In Leander, Texas, trapping wild animals (including feral cats) is illegal, but authorities have ignored the rules for groups that run TNR programs. One citizen, Carmen Amaya, is leading a charge to get authorities to start enforcing this so that TNR programs can't happen. The main reason appears to be that she's upset her dog was scratched by a feral cat and ended up with $800 in vet bills (not something I'd be happy with either, but is this really the best way to direct her anger?).

A non-profit group, Shadow Cats, has led the TNR effort and has trapped, neutered and vaccinated  about 3000 cats in Central Texas since 2004. About 500 were adopted and the rest released. The organization knows they are working outside the law and have lobbied for it to be changed. That was being considered in June, but opposition from Amaya and others has led to the creation of a task force to make a recommendation, which is due next month. In the meantime, Shadow Cats has ceased activities in Leander.

I'm not sure what the opponents to TNR really want. If it's just cessation of the program, there's no benefit to them.  Without the program:

• Stray cats will continue to be around, and there will probably be more of them.
• Potentially adoptable cats won't be taken into homes to improve the lives of those cats.
• Vaccine coverage of the population will decrease. That's a critical point, because it will result in lower "herd immunity."   With herd immunity, the greater the percentage of a population that is immune to a disease (i.e. vaccinated), the lower the likelihood of the disease establishing itself in and spreading through the population, even among those individuals who don't get vaccinated.

On the other hand, if these people simply want Shadow Cats to stop releasing the neutered cats back into the neighbourhood, it means either 1) finding a way to care for all those cats in shelter, which simply isn't realistic for a multitude of reasons, not the least of which is cost, 2) releasing the cats elsewhere, which doesn't actually solve the problem, it just makes it someone else's, or 3) euthanizing all the cats instead of neutering and releasing them.  If they're hoping that by objecting to the TNR program that all the cats being trapped will be euthanized instead, they need to realize:

• It's not going to happen as long as volunteer "rescue" groups are in charge of the program. These groups aren't going to trap and kill.
• The city is unlikely to do it either, and there's a cost to having city personnel catch the cats and take them somewhere to be euthanized.
• Most importantly, culling has been shown time and time again to be an ineffective way to control feral animal populations. What's needed is a combined approach that includes measures such as neutering and vaccination, education to reduce the risk of human and domestic animal exposure to feral animals, and taking steps to discourage feral animals from spending time in close proximity to people and domestic animals.

Amaya states that "her" feral cat is a nuisance and she doesn't want it on her property. So what is she trying to accomplish? If anything, her actions will just help her single stray cat turn into a large extended family of stray cats that are susceptible to rabies.

There are certainly concerns with feral cats and TNR programs. They are not perfect and not always run well. Some people are opposed to them for various reasons, some of which are quite reasonable. It's a tough issue because one person's idea of success might be completely different from someone else's. Some people focus on the number of animals, while others focus on the quality of life of the animals, public health aspects, impacts of feral cats on wild bird populations and other diverse areas. A local council isn't going to be able to solve these problems, and it really comes down to an assessment of the potential usefulness of the program and the ability of the people involved to do it safely, ethically and legally.

Personally, I'd rather see well-designed, well-run and regularly-evaluated programs to try to reduce feral cat (and dog) populations, and (perhaps more importantly) increased vaccination coverage in the feral animal population, than nothing. Feral animals aren't going to disappear if we ignore them.

Image source: www.shadowcats.net

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Bali's rabies outbreak continues to claim lives, largely because of inadequate access to proper healthcare. The death toll from this outbreak, which has been ongoing for about two years, is officially 58, although the true count may be higher.

The latest case was a 57-year-old temple priest who was infected after trying to break up a fight between strays dogs and his puppy.  He was bitten by a stray dog in the process, but did not receive any post-exposure rabies vaccination because of a vaccine shortage. Rabies is basically 100% preventable when proper care is provided after an exposure, but inadequate access to proper treatment remains a problem, particularly in certain areas and in less developed countries. The priest started to develop signs of rabies about two months after the bite, which is a pretty typical time frame. Once signs of rabies are present, it's almost invariably fatal, and he unfortunately succumbed to the disease shortly after being hospitalized.

Despite ongoing efforts to control this outbreak, rabies remains a serious problem in Bali, and many stray dogs remain unvaccinated. Inadequate education of the public is a problem since not everyone who is bitten goes to a doctor, especially for minor bites. However, even if people go to a doctor, the shortage of rabies vaccine is a huge problem. This whole situation is clearly not under control.

Visitors to Bali need to be aware of this ongoing outbreak. If you are traveling to Bali:

• Avoid contact with stray dogs. You never know who's rabid.
• If you are bitten, promptly clean the wound and get to a physician.
• If you are bitten by a stray, make sure you get post-exposure treatment: a shot of anti-rabies-antibody and 4 (previously 5) rounds of vaccine over a few weeks. If you can't get the treatment started in Bali, get it as soon as possible. Rabies exposure is not an emergency, but you don't want to unnecessarily delay treatment. You don't need to be immediately evacuated from the country to a place you can be treated, but at the same time, you don't want to take your time, travel for a while, then get vaccinated a week or two later. You'd probably be fine, but rabies is not something with which to take chances. The incubation period is variable and the rapidity of onset depends in part on the severity and location of the bite. In particular, a severe bite to the head or neck region would be an indication for very prompt treatment. So, if you're bitten, don't panic, but try to get back home and get treated as soon as is reasonably possible.

Rabies vaccination of people planning on visiting Bali is not recommended, unless you are planning on having contact with dogs. If you are going to Bali to take part in stray dog vaccination, then rabies vaccination would absolutely be indicated. Otherwise, it's not really something that's needed. If you don't get bitten, you won't get exposed, and a little common sense goes a long way toward avoiding dog bites.

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My parents adopted a cat from their local OSPCA shelter the other day. He's an adult cat (maybe named by now, but not at last report) and he came:

• neutered
• vaccinated against the typical group of feline diseases
• dewormed with fenbendazole
• treated with metronidazole (an antibiotic - it wasn't clear whether this was because he had diarrhea at some point or was diagnosed with something, or whether it was just a routine practice)
• treated with Revolution for flea control

The one thing that's missing from the list is vaccinated against rabies, which I find amazing. Apparently, the cat was given everything they can give at the shelter without the need for a veterinarian. (Presumably the cat came in neutered, because that would hopefully fall under the "need a veterinarian to do it" category. Prescribing an antibiotic would also be something I'd hope would involve a veterinarian.)

Sending cats to new homes without vaccinating them for rabies is bad practice. Rabies is a rare but extremely serious disease. Vaccination is critical, safe and easy. The OSPCA website says that not all shelters vaccinate against rabies. Some shelters have veterinary staff in the facility, so rabies vaccination would be standard there. Other shelters work with local vets to do this, but that's not universal, apparently. I don't see why this isn't a mandatory policy for the OSPCA. Yes, there is a cost to it, but that should be a cost of doing business. Rabies vaccines aren't expensive and many vets would work with groups like this to keep the costs down. Adopting an animal from a shelter isn't cheap, and recovering the small added cost of the vaccine should be possible. I'm not sure whether it really is a question of cost, accessibility or simply not bothering. Getting a veterinarian involved also has benefits beyond just giving the vaccine. Potential health problems can be identified, including diseases that could be transmitted to people that adopt the animals.

It's true that lack of vaccination of adopted pets can be addressed by getting them vaccinated right after adoption. Any pet that has been adopted (or purchased, or otherwise obtained) should be promptly examined by a veterinarian to identify any potential problems, and to make sure the pet is on a proper preventive medicine program. Realistically though, not everyone does this. While you don't like to set policies according to the lowest common denominator, you need to for a deadly disease like rabies when the consequences to people and pets are so high. I find it hard to justify sending any animal out of a shelter without rabies vaccination.

Image source: www.ontariospca.ca

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A large rabies outbreak continues in Moscow.  There were 257 rabies cases reported in the area in 2009 - ten times the number from previous years, and well above the very low numbers that occurred for a decade of so after an aggressive control program to control the post-World War II rabies epidemic. Control of that outbreak mainly involved shooting of potential rabies vectors: stray dogs, foxes and raccoon dogs. 

Various more humane but still aggressive control measures are being considered to help control the current epidemic, including banning movement of pets to suburban cottages (probably better to just vaccinate the pets first), canceling a dog show (pretty low yield - better to vaccinate), and mass immunization of wild and domestic animals (the key approach).

An aggressive approach makes sense. Rabies is almost invariably fatal and large numbers of people who are exposed require post-exposure treatment every year.  Local wildlife population patterns, wildlife rabies hotbeds and rates, pet numbers, pet movement and vaccination must all be considered when determining the best approach to control. Apparently, about 30 000 pet dogs visit cottages in the Moscow area each weekend, and there's concern that they could bring rabies back to the city with them. Authorities have warned about traffic jams that might develop, presumably from police stopping traffic looking for contraband canines. However, instead of banning dog movement, it would likely be more effective to increase vaccination (or even mandate it for dogs in those high risk regions) and control roaming dogs. If a dog doesn't roam freely in the country, it's less likely to encounter a rabid animal. If it's vaccinated, it's unlikely to get infected if it does get exposed. If it's not allowed to roam when it returns to the city, it's less likely to spread rabies to other animals and people in the very rare event that it was exposed and infected. Furthermore, if wildlife are vaccinated through rabies bait drops, the chances that a roaming dog will be exposed get even lower.

Ensuring the highest possible canine vaccination rates is the key measure. Whether that's through mandating vaccination, providing it at low cost, or making it more convenient for owners to get it done, it's a great place to focus efforts and resources. In principle, it's a simple concept. In practice, it can be more difficult, especially when compliance of the general public is required.

For those of you that want to practice your Russian reading skills, here's the original story.

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The Toronto Star had a front page article today about an ongoing distemper outbreak in raccoons, and the potential effects on dogs. Toronto's not alone, as there are distemper outbreaks underway in many different municipal regions.

Distemper is an infection caused by a virus that is related to human measles virus. It mainly affects dogs, raccoons and ferrets. It can cause intestinal, respiratory and neurological disease, with neurological problems being the most severe. Vaccination of dogs against distemper is highly effective, and has greatly reduced the impact of this virus on the pet dog population.

Distemper cannot be transmitted to people, so the disease itself is only an animal health risk. However, there's an indirect effect of which people need to be aware. Rabies always needs to be considered in dogs and raccoons that have signs of neurological disease. If there is so much distemper in an area that people assume every sick (wild) animal they find has distemper, there is a risk that the odd (but important) case of rabies may be missed, leading to human exposure. It's easy to dismiss a neurological raccoon or unvaccinated dog as having distemper, and it usually is distemper (particular in light of the current outbreak), but the implications of missing a case of rabies can be severe since it can be transmitted to people and is almost invariably fatal.

If distemper is present in your area (or, really, even if it's not currently a problem):

• Make sure your dog is vaccinated.
• Keep your dog away from wild animals, especially ones that are acting strangely.
• Keep yourself away from wild animals, especially ones that are acting strangely.
• Don't do things that will encourage raccoons to move into your yard, like leaving out food.
• If you see a wild animal that is acting strangely, call your local animal control agency.

Photo credit: The Star - Toronto edition 18-Feb-10

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The medical journal Lancet has fully retracted the flawed 1998 study that raised a link between MMR (measles, mumps, rubella) vaccination and autism in children. This study fueled incredible debate and was a driving force in the anti-vaccination movement, and subsequent declines in vaccination rates were a key reason for the resurgence of measles. It also fostered general anti-vaccination sentiment that has continued to affect decisions regarding vaccination of people and animals.

The study has come under fire for years and has been highly controversial, with strong opinions on both sides. In 2004, the journal issued a partial retraction based on a conflict of interest of Dr. Wakefield's (the lead researcher), since it was revealed that he was being paid by lawyers acting for parents who believed their children had been harmed by MMR vaccination. The new full retraction goes much beyond this, and is based on problems that have been revealed with the scientific method, reporting of what was done, plus ethical issues pertaining to ethical committee approval.

The UK's General Medical Council ruled last week that Dr. Wakefield had shown "callous disregard" for the children involved in the study and acted "dishonestly."  He faces being stripped of the right to practice medicine in the UK. Accordingly, all of the findings of this study are considered invalid.

Image source: http://www.dailymail.co.uk

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Rabies has been diagnosed in a 6-week-old Jersey calf at a Maryland educational centre, raising concerns about exposure of farm visitors, particularly groups of school children. At least 70 kids and an unstated number other visitors had recently visited the farm.

Fortunately, the farm in question is not open to the public, so they should have an easier time identifying people who have been there (e.g. school groups). Contact tracing is underway to try to identify people that had contact with the calf. Simply petting the calf or being in the general area does not pose a risk. The main risk would be from contact of open wounds with the calf's saliva, or a bite. We don't typically associate bites and calves, but it can happen when calves are allowed to suck on someone's fingers - if the person sticks their hand in too far he/she may get chomped by the calf's sharp molars. Public health personnel are trying to identify people who had contact with the calf, then they'll determine whether there was a chance of exposure to the virus. People that were potentially exposed to rabies will undergo post-exposure prophylaxis, consisting of a shot of anti-rabies antibodies and four doses of vaccine over the course of a month. Not fun, but much better than getting this almost invariably fatal disease. At least nine students have started treatment so far.

Petting zoos and similar events are a concern in terms of disease transmission because of the large number of people that can be exposed to animals and the high percentage of children that are involved. Rabies is uncommon in petting zoo animals, but it is periodically identified at such a facility/event, often resulting in the need for post-exposure treatment of large numbers of people. Vaccination of petting zoo animals against rabies should be a standard practice. This calf, being only six weeks old, was too young to vaccinate, but if the calf's mother was vaccinated the risk of rabies would be lower (because the calf would get antibodies from the mother). There's no information about the cow's vaccination status or much else about the calf, apart from it being a recent acquisition.

The fact that a recently acquired young calf was allowed to have contact with the public is questionable management, because young calves are a high risk group for certain infectious agents like Cryptosporidium and Salmonella. The CDC recommends that children less than five years of age not have contact with young calves.  Since young kids are frequent visitors of places like this, having calves (or at least letting people have direct contact with them) is quite questionable as well. Hopefully there will be a good review of vaccination, animal acquisition and animal contact protocols for this facility to reduce the risk of future exposures to rabies or other infectious diseases.

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.A Texas couple is undergoing rabies post-exposure prophylaxis after an abandoned puppy they adopted was diagnosed with rabies. They found the puppy outside and brought it into their house. One of them was subsequently bitten and they found out about the rabies diagnosis on Christmas eve.

One of the couple is quoted as saying "The doctor said 'It was a good thing they didn't wait until Monday, because it would have been too late. We couldn't have given you the shot because it wouldn't have done any good. You would have been dead within 48 hours." I really hope they completely misinterpreted what the doctor said, otherwise the doc has no clue about rabies. Prompt treatment is the goal, and you certainly don't want to wait any longer than you have to, however rabies doesn't kill in 48 hours, and you can start post-exposure treatment any time (just the sooner the better).

The couple also have seven other pets, who may also have been bitten. There wasn't any comment about what's happening to those pets. Hopefully they are properly vaccinated so they can be given a rabies vaccine booster and only undergo a short-term "quarantine" at home with the owners. (The alternative is immediate euthanasia or strict, long-term quarantine for months).

This isn't a new scenario - adopting a stray animal then finding out it has rabies. The less you know about an animal at the time of adoption, the greater the risks. I'm certainly not saying don't adopt a stray animal. But, if you are going to do it, recognize the risk, make sure you are in a low-risk household (everyone's susceptible to rabies, but some people are at greater risk for other zoonotic diseases and stray adoptions should be avoided by them), get the animal examined by a veterinarian as soon as possible, and make sure that it gets examined by a veterinarian if it develops any signs of disease.

All this leads into another another story I read a few days ago. Basically, it was a feel-good story about someone who found some puppies, stopped by a nursing home (or similar facility) and the facility adopted one or more of the puppies. This demonstrates some good points (e.g. resident's presumably had a great time watching the pups) and bad points (e.g. disease exposure, unknown temperament, injury risks from rambunctious puppies...) of animals in long-term care facilities. What if the puppies that were adopted by the home had rabies? It's happened before, and you end up having to administer post-exposure prophylaxis to a large number of people that already have enough health issues and risks. Nursing homes and other facilities should never adopt stray animals. Hopefully we don't see a news release in the next few weeks about widespread rabies exposure in that facility. 

 Video from wfaa.com

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If an unvaccinated person is exposed to rabies (usually by a bite), they undergo post-exposure prophylaxis (PEP), consisting of an injection of anti-rabies antibodies and a series of 4 or 5 vaccines. (It used to be 5, but it was recently recommended to drop this to 4). This is a highly effective protocol which basically guarantees that the person won't get rabies IF the person is treated promptly.

If an unvaccinated pet is exposed to rabies, the situation is much different. The two options are euthanasia or a strict six month quarantine and a single dose of rabies vaccine either immediately or after 5 (of 6) months of quarantine.

So, if there is a  post-exposure treatment for people that is basically 100% effective, why don't we do the same thing in dogs and cats?

There are a few possible explanations for this:

1) Rabies is almost invariably fatal. The significant public health risks take precedence over animal health and pet owner inconvenience, stress and pet loss.

2) There is limited information about PEP in dogs, and results have been mixed.

• In one study (Hanlon et al 2002), experimentally-infected dogs were treated with various protocols. Treatment with rabies antibodies on day 0, followed by vaccination on days 0, 3, 7, 14 and 35 was effective at preventing rabies in 5/5 dogs - a good result, but the small number of dogs tested (5) prevents us from drawing any broader definitive conclusions. Rabies antibodies alone protected 4/5 dogs. All dogs that did not receive the antibodies but were vaccinated on days 0, 3, 7, 14 and 35 died of rabies.
• In another study (Manickam et al 2008), all exposed dogs were protected by rabies vaccination on days 0, 3, 7, 14 and 28. A 3-dose regimen (days 0, 5 and 28) was protective with one vaccine but not another.

Clearly, based on the limited number and small size of these studies, and the differing results, we cannot recommend a canine PEP protocol with confidence. However, these studies strongly suggest that PEP can be effective in dogs, and I think we need to consider when and how to use it. I wouldn't necessarily use PEP to replace quarantine without more evidence (i.e. field studies). I think the use of PEP to help protect the dogs while maintaining quarantine to protect the public is a good start. If canine PEP can be shown to be as effective as PEP in people, then some day quarantine might not be needed.

Regardless, this situation highlights the need for current vaccination of all dogs and cats in rabies-endemic areas. If a vaccinated animal is exposed to rabies, there is no requirement for euthanasia or long, strict quarantine. Rather, standard guidelines recommend giving the pet a rabies vaccine (booster) and having the animal observed by their owner for a period of 45 days. Developing better PEP protocols for unvaccinated animals is useful, but I'd prefer to see it become a moot point as a result of high vaccination rates.

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An article in an upcoming edition of Transplant Infectious Disease (Gisel et al) describes a case of Bordetella bronchiseptica pneumonia in a person who had received a kidney and pancreas transplant. This person had to board her dogs at a veterinary clinic while she was hospitalized for a bowel obstruction that occurred after surgery. The clinic required her dogs to be vaccinated against Bordetella bronchiseptica, a cause of canine "kennel cough." They were vaccinated intranasally (i.e. up the nose) with a modified live vaccine comprised of live B. bronchiseptica that is modified so it is unlikely to cause disease but can still induce a good immune response. The owner developed pneumonia after returning home and B. bronchiseptica was isolated. Specific testing was not performed to confirm that the vaccine strain caused disease, so it's possible that she was infected by the normal (i.e. "wild type") B. bronchiseptica (which still would have presumably come from the dogs).

Immunosuppressed individuals are at high risk for infection by microorganisms that usually don't cause disease in otherwise healthy people. Bordetella bronchiseptica is a good example of this. Care should be taken around pets by anyone whose immune system is compromised. Here are some recommendations pertaining to kennel cough vaccination:

• Immunosuppressed individuals should not receive modified live vaccines themselves, and it is probably prudent to extend this recommendation to avoid modified live vaccination of their pets with vaccines like the Bordetella (kennel cough) vaccine.
• If vaccination for kennel cough is required for entering a kennel or vet clinic, an exemption should be sought because of the potential risk to the immunocompromised person.
• If vaccination must be performed, injectable vaccination is preferred. It doesn't produce as good immunity in the dog compared with intranasal vaccination but the risks to the immunocompromised owner would be much less.
• If intranasal vaccination with modified live kennel cough vaccine is used, immunocompromised owners should not be in the same room during vaccination. They should avoid contact with the dog's mouth, nose and face for at least a few days after vaccination and should wash their hands (or use a hand sanitizer) regularly after contact with the dog.
• If respiratory disease develops in someone exposed to a dog recently vaccinated against kennel cough, the potential for vaccine-associated disease should be mentioned to the physician.

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A study in the Journal of the American Veterinary Medical Association (Murray et al 2009) investigated the rabies vaccination history of dogs and cats diagnosed with rabies in 21 US states between 1997 and 2001. 

• 264 rabid dogs and 840 rabid cats were identified.
• 4.9% of rabid dogs and 2.6% of rabid cats had a history of rabies vaccination.
• Of the 13 dogs that had been vaccinated, only 2 were considered currently vaccinated. Similarly, of the 22 previously vaccinated cats, only 3 were currently vaccinated.
• Texas had the most positive dogs while Pennsylvania had the most positive cats.

This study cannot determine how effective vaccination is. You'd need to know the number of animals that were and were not vaccinated, and then the number that did or didn't get rabies to determine efficacy. The fact that a small number of properly vaccinated animals got rabies shows the vaccine is not 100% protective, which is not surprising.

Vaccination is an important part of rabies prevention, but it's not the only part. Vaccination is a last line of defense - avoiding exposure to rabies is the critical first line. To reduce the risk of rabies exposure, keep your pets under your control at all times. Keep bats out of the house and try to ensure that your house and yard are not welcoming to wild animals. Don't let your pets have contact with wildlife and pay close attention when strangely-acting wildlife are around. Active measures to reduce wildlife rabies such as rabies baiting are also important.

Don't assume because your pet is vaccinated that you don't have to worry about trying to reduce the risk of exposure to rabies.

Don't assume that an animal with neurological disease doesn't have rabies just because it's been vaccinated.

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Norfolk, VIrginia's MyCityTalk.com has an article entitled "The Truth About Pet Vaccinations". It's basically the same as hundreds or thousands of other articles available on the internet purporting to try to set the unwary pet-owning public straight about pet vaccines. Here are some of the highlights.

The evidence against vaccinating, however, is overwhelming.

• What evidence? Someone's commentary? Sure, there are hundreds of those. Real scientific proof? Nope. No one is going to dispute that vaccine reactions and other problems can occur. That's clear. At the same time, vaccines clearly save lives and reduce illness. There is certainly a cost-benefit to consider, but non-evidence-based statements like this don't help. The risks and benefits do need to be considered when designing a vaccination program. Real evidence should be used, however.

It is more and more common to see cancer in dogs and cats under 5 years of age.  Autoimmune diseases are on the rise as well.

• Maybe, although you have to be careful interpreting that. We have much better diagnostic tests now and can detect diseases we couldn't diagnose before. Also, animals that are alive because they didn't die of an infectious disease are able to develop these conditions.  You cannot simply attribute such a trend to modern vaccine practices without looking at the other factors that may be involved.

Vaccinations do help prevent serious illnesses, but they should be used with restraint.  Before vaccinating, consider the risk.

• Absolutely. Best piece of advice in the article.

If your cat is indoor only and will never be exposed to unvaccinated animals, the risk of infection is low.

• While the risk of exposure is LOWER for indoor cats, it's not zero. It's amazing how many "indoor" cats come into vet clinics after being hit by a car or getting into a fight with a wild animal. Indoor cats can escape. Also, other animals can get inside, particularly bats - a source of rabies exposure.

Request individual vaccines and vaccinate at least three weeks apart if possible.

• There's little to no evidence that using combination vaccines is a bad thing for your average pet. Also, individual vaccines aren't available for all diseases. Further, if you only vaccinate for one disease at a time and space them three weeks apart, it's going to take a longer time to have an animal with protective immunity. It makes it a lot more expensive too.

If your cats go outside and you have rabies in your area, give a rabies vaccine at six months of age.

• This sentence should start at "give."  Every animal in an area where rabies may be present must be vaccinated, regardless of whether it goes outside.

Vaccinations do not need “boosting”

• Says who? This is a generalization that can cause problems. For some vaccines in some animals, a single dose may be adequate, but it's certainly not true for all. Some vaccines work better than others. Some diseases are more amenable to good vaccination prevention. Some vaccines are probably good for a long time, if not life-long. But not all of them.

Simple blood tests can determine if your companion’s antibody levels for parvovirus and distemper remain high enough to resist infection.

• Nope. You can determine antibody levels but no one really knows how to interpret them (i.e. what level means the animal will be protected). Antibodies are only one component of vaccine protection.

The currently licensed leptospira bacterins do not contain the serovars causing the majority of clinical leptospirosis today, so it is generally not a useful vaccine. 

• That's true for certain areas. In some regions, the vaccines strains are protective for the strains causing disease.

Homeopathic Nosodes are an alternative some guardians are using when choosing not to vaccinate. 

• There is no evidence whatsoever that nosodes do anything but make money for people who sell them.

They (nosodes) do not produce titers against these diseases like a vaccination.

• That's because they don't do anything.
  

Never vaccinate a sick or weakened animal.

• Good advice.

Educate yourself.  Your veterinarian cannot make this decision for you, nor should they.  You are your companion’s guardian.  It is your responsibility to give them the best care you can by researching and carefully weighing your decisions about their healthcare.

• That's true. However, you need to make sure you get good advice from all sources. You should consult with your vet and feel free to ask any questions. You should also scrutinize information available on the internet. Vaccination recommendations have changed in recent years, with longer intervals between boosters, and they certainly may change further as we learn more. I'm perfectly happy stretching out vaccine intervals based on good data. My pets don't get vaccinated every year. The key is to base decisions and changes on evidence so that we maintain the effectiveness of this critical disease-prevention tool.

The original source of the article was actually the Healthy Pet Journal, an online "journal" (site) published by a holistic/naturopathic veterinarian (who of course runs a clinic specializing in such services).  Always consider the source of what you're reading and the potential biases that come along with it.

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In the wake of the death of Dr. Alister Rodgers from Hendra virus, there have been increasing calls for the Australian government to put significant resources into Hendra virus research. Various areas need to be investigated, including how this virus is maintained in the bat population, how it is transmitted from bats to horses, ways to treat infection and ways to prevent infection. Vaccination is an obvious topic, and creation of a vaccine appears to be possible. However, as I wrote the other day, there's a question about whether a company would put millions of dollars into development of a Hendra virus vaccine for people, given that the disease is very rare, is currently limited to one region, and only appears to be a risk for people in close contact with sick horses.

One thing that needs to be considered is whether it may be better to develop a vaccine for horses rather than people. Think about it:

• All reported human Hendra virus infections have come from people in close contact with sick horses.
• Human vaccines are very expensive to develop, test, get approved and market.
• Vaccines for animals are much cheaper to make because testing and regulatory requirements are not as strict. (This can lead to marketing of vaccines for animals with limited evidence of effectiveness, but the upside is that vaccines can get to market quicker and with less expense.)
• People are often more willing to get their horses vaccinated than to get vaccinated themselves.

So, even though it might sound strange, development of a Hendra virus vaccine for horses may be a more effective way to protect people.

If this approach is taken, a key step would be continued research into the epidemiology of Hendra virus infection to investigate other routes of human exposure. If people can get infected by other routes, vaccination of horses obviously wouldn't address the entire problem. However, based on what we know currently, vaccination of horses might be the most effective, timely and economic response to this pressing problem.

This Worms & Germs blog entry was originally posted on equIDblog on 04-Sep-09.

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

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

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

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

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

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

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

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In Canada, access to rabies vaccine for animals is restricted to veterinarians (i.e. only vets can buy the product itself and administer it to people's animals). In general, this is an excellent approach because it ensures that the vaccine has been handled and stored appropriately, animals have been vaccinated properly and accurate vaccination records are kept. I certainly wouldn't want rabies vaccine freely available, whereby anyone could buy vaccine, handle it poorly, vaccinate their animal improperly, and yet believe or claim to have a properly vaccinated pet.

The problem with this restriction is the fact that veterinary care is not always available. Specifically, I'm referring remote northern communities that do not have veterinary care on a regular or even a sporadic basis. I received an e-mail the other day from a medical professional in a fly-in First Nations community in Northern Ontario. They have not had a visit from a vet in a while, so the dogs there aren't vaccinated. Unfortunately, a dog was attacked by a wolf recently so it must be considered possibly  exposed to rabies, resulting in euthanasia or long quarantine. The question was about what can be done in those communities to provide rabies vaccine for people's animals. I didn't know, so I inquired with the Canadian Food Inspection Agency, the federal agency in charge of all-things-rabies.

There are actually provisions in Canadian regulations for situations like this (a provision in the Health of Animals Regulations Section 132.4 (2), if you want to know specifically). This allows rabies vaccine to be sold in accordance with written permission granted by the Minister, in specific circumstances such as in a remote area where veterinary services are not readily available. The provincial veterinary association is typically contacted to determine whether or not there is a veterinarian who could arrange to do the vaccinations. If the provincial association agrees that there is no veterinary service available to the community, then permission can be granted to purchase vaccine. 

It's quite a reasonable and logical approach that allows for access to rabies vaccine when needed, but has enough controls in place to ensure that this can't lead to abuse of the exception. People in remote communities in Canada should be aware of this. Some communities get periodic visits from vets but there are many others such as the one in this case that don't have any direct access to veterinary care, and this is a way of at least providing protection for people and pets against rabies.

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Two kids and one adult are undergoing post-exposure treatment for rabies after having contact with an infected kitten. One child saw the stray animal and went to give it some food, and he was bitten in the process. The kitten then proceeded to bite the boy's mother and another child in the neighbourhood. Fortunately, the kitten was taken to animal control and was identified as a rabies suspect. It was euthanized and testing of the brain confirmed it had rabies. Accordingly, the three bitten people are now undergoing post-exposure treatment. Animal control is handing out flyers in the neighbourhood to warn others, as there may be more rabid animals in the area. One particular concern with young kittens is that sometimes multiple animals from the litter are infected, so there may be more cute but deadly kittens in the area.

• Avoid contact with stray animals. That's the best way to avoid getting bitten by one.
• If you are bitten by a stray animal, the animal must be caught and quarantined. If you don't know the rabies status of an animal that has bitten you, you have to consider it rabid and get treated. If you are bitten by a stray or wild animal, call animal control to catch it. If you can safely contain it (e.g. lock it in a garage) without putting other people at risk, do so and then wait for animal control to capture the animal.
• Vaccinate your pets.

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A canine influenza virus vaccine has recently been released. Canine influenzais a virus that originated from a horse influenza strain and is now circulating in some dog populations. (To my knowledge, we have yet to find it in Ontario. We didn't find any evidence of it in an earlier surveillance study). It typically causes mild disease, as with influenza in people, but can also cause serious (including fatal) infections. These cases are most common in densely-populated, stressful environments like shelters and racing greyhound facilities.

Like most vaccines, this canine influenza vaccine does not claim to provide 100% protection. Veterinary vaccines can get conditional licensing and be marketed with little evidence of effectiveness. The manufacturers have produced data "supporting product purity, product safety under normal conditions of use in field safety trials and demonstration that the product has a reasonable expectation of efficacy." That means they have shown the vaccine is produced with good practices, had no obvious adverse effects in a safety study, and there is a possibility that it could be effective (presumably from showing vaccinated dogs produce antibodies against canine influenza virus). During the conditional licensing period, the manufacturers "will continue to submit data obtained in support of the product’s performance, which will be evaluated by government regulators to determine whether a regular product license may be issued."

There's a good likelihood the vaccine will be effective at reducing the incidence and severity of disease, as with influenza vaccines in other species. Basically, if a vaccinated dog gets exposed to the virus, it should be less likely to get sick, and if it gets sick, it should be less likely to have severe signs. Reducing the incidence and severity of influenza also has the benefit of reducing the chances of developing a secondary bacterial infection, which can cause very serious disease.

Deciding whether to vaccinate your dog largely comes down to the risk of exposure and the implications of your dog becoming ill. In an otherwise healthy dog that is not in a high risk environment (e.g. kennel, shelter, greyhound racetrack), it's questionable whether vaccination is needed. If canine influenza virus is in the area, it's something to consider, but the virus seems to be rare (or at least rarely identified) in pets in most regions. Discussing the risks and benefits with your veterinarian is the key.

Canine influenza is NOT considered a zoonotic disease. There is no evidence that it can infect humans. Therefore, there is no public health argument for vaccination.

Image source: www.petinsurance.com/healthzone/pet-articles/pet-health/Canine-Influenza.aspx

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At the same time that the country is drafting an animal welfare law that would ban widespread killing of dogs, a Chinese city has killed 36 000 stray and pet dogs in an effort to eliminate rabies. Since late May 2009, more than 6 000 people in Hanzhong have been bitten or scratched (presumably by dogs), and 12 have died of rabies. Certainly, this indicates multiple problems. One is the massive number of bites and scratches. Contributing factors probably include a large stray animal population, limited routine animal control efforts, and inadequate education of the public regarding bite avoidance. The number of injuries and deaths certainly indicates that an aggressive response is needed. However, there is little evidence that culls (i.e. mass killings of this type) have any effect on controling rabies and animal-associated injuries. Efforts are probably better directed at other forms of population control, vaccination of stray and pet dogs, and education of the public to keep stray dogs away and reduce the risk of bites. These types programs cost money, but the costs of treating 6 000 bites and 12 fatal rabies infections can be enormous. I don't know how many people received post-exposure treatment for rabies, or what such treatment costs in China, but it's estimated to cost  about $1500 per person in North America. That would pay for a lot of rabies vaccine for dogs.

Photo: Hanzhong, China (source: www.panoramio.com)

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The latest issue of Oprah's magazine "O" features the icon talking about her recent puppy dog adoption drama involving canine parvovirus. It just goes to show that even the pets of the biggest celebrities in the world are not beyond the reach of common microscopic infectious pathogens.

A couple of months back, Oprah adopted two cocker spaniel puppies from a shelter in Chicago. Unfortunately, within two weeks they both came down with parvovirus infection and had to be hospitalized. I'm sure both dogs received top-of-the-line care with no expense spared, but even so one of the puppies died. The other puppy came very close to dying as well, but happily she apparently has now recovered completely and is doing just fine (or quite likely better than fine, considering who her new owner is!).

Oprah also mentioned how one of her other dogs, Solomon, also suffered from a parvo infection years ago, but that dog was over a year old when he became ill. It's actually quite unusual for any dog to get parvo beyond one year of age - most adult dogs are not affected by the virus, unless perhaps their immune system is compromised for some reason.

These stories bring up a few interesting points to ponder:

It's great to adopt an animal from a shelter and give a homeless animal a home. It is an act of great kindness that I don't want to take anything away from in the least. However, it's important to realize that you never know what shelter dogs may be carrying, nor how well vaccinated they are.

• Even if the animals are vaccinated once at the shelter, the protective effect may be less than ideal if a properly timed vaccination series is not completed.
• In this case the pups may have been exposed to parvo after leaving the shelter, but they could have just as easily been exposed at the shelter, which begs the question of what else might they have been carrying? Bacterial pathogens such as Salmonella and Campylobacter are also particularly common in young dogs and cats (even healthy ones), and these are potentially zoonotic agents.

Young animals, particularly from shelters, are higher risk in terms of the infectious diseases they can carry and transmit. That doesn't mean they shouldn't be adopted, but it does mean taking some extra precautions for the first several weeks they're in their new home. These include being very diligent about controlling stool contamination of any kind (which can be easier said than done during the house-training phase), preventing contact with high-risk individuals (e.g. young children, the elderly, anyone with a weakened immune system) and lots of handwashing on the part of everyone involved with the puppy (or kitten!).

Parvo is a very serious disease in puppies, yet people sometimes become a little complacent about vaccinating for parvo and other puppyhood diseases.   Remember, though, that the reason parvo has become so much less common than it used to be is largely because of widespread and effective vaccination.  I have to wonder about how well vaccinated Oprah's dog Solomon was to get the disease at the age he did, but there could easily be other factors involved as well.  The virus is still out there, and if we become lax in our infection control practices - including decreasing exposure of puppies to the stool of other dogs, as well as vaccination - it's waiting in the wings for its opportunity to move in. Even with the very best care the infection can still be fatal.

It's also relevant to note that, as demonstrated by Solomon's case, just because parvo is very uncommon in adult dogs doesn't mean it's impossible for them to get it.  It's important to always remain diligent.

Parvoviruses are quite species specific, so thankfully people cannot get parvovirus from dogs, but remember that puppies can get diarrhea from pathogens like Salmonella, which can be transmitted to people. There is also a human parvovirus which is the cause of Fifth disease. Just like the dog virus cannot infect people, the human virus cannot infect dogs.

Image source: http://omg.yahoo.com

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Rabies vaccination is supposed to be given at regular intervals - typically every 1 or 3 years, depending on the vaccine. Some people don't want to vaccinate their pets on a regular basis, but they may not understand all the implications of this decision. Often, people ask whether antibody levels (titres) can be checked to determine if repeated vaccination is necessary or if it can be delayed longer. However, rabies is covered by very straightforward government regulations in Canada (and presumably in many other regions).  According to these regulations, checking vaccine titres is not considered an acceptable alternative to regular vaccination.  Knowing this, here are two scenarios to consider:

1) Your pet bites someone.

After a pet bites anyone, it must be monitored for 10 days to ensure that it does not develop signs of rabies. It makes no difference whether the animal is vaccinated or not. However, if you do not have proof that your pet has been properly vaccinated, in Ontario, it is theoretically possible that you could be charged under the Health Protection and Promotion Act.

2) Your pet is exposed to a rabies suspect.

If your pet was vaccinated, you'd have two options. Most commonly, your pet would receive a booster vaccine and would be observed at home for 45 days. Alternatively, if you wanted to avoid a booster, you could take a blood sample to check the rabies titre. If a protective titre (>0.5 IU/ml) was present, there would be a 45 day observation period. If a protective titre was not present, the pet would be treated as unvaccinated.

If your pet was not vaccinated, it would be subject to a strict six-month quarantine or euthanasia.

If your was vaccinated at some point, but not vaccinated according to the vaccine manufacturer's guidelines (i.e. it didn't receive the appropriate 1 or 3 year booster),  it would be considered unvaccinated, and be subject to the same 6 month quarantine. It would not matter if the rabies titres had been checked and a protective titre had been present in the past.

From this, it should be clear that there are serious implications of not vaccinating your pet, at least in Canada. There are some circumstances where you may be rightfully hesitant to vaccinate your pet, such as if your pet previously had a severe vaccine reaction. However, if you choose not to vaccinate, you must be aware of the implications of this decision. Neither a letter from your vet stating that vaccination would be risky nor annual rabies titre checks are going to be of any help at all because of the rules that are currently in place.

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

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The Cherokee Scout reported a story about a North Carolina man that was attacked by a rabid fox in his own home. It seems he was awakened one morning by scratching at the front door. Thinking it was his cat, he opened the door, only to be greeted by a rabid fox that bit "plumb through [his] big toe", rampaged around the house, then bit his other foot. He killed the fox using a mop handle (definitely self defence), and it tested positive for rabies (no surprise here!). This was the sixth confirmed case of rabies in the county since March 16, 2009, indicating that people in that area should be particularly cautious. Marshall Duggan, the man that was attacked, was treated for his bite wounds and is now undergoing rabies post-exposure treatment. The morals of the story are:

• Be wary of rabies, particularly when an outbreak is underway. Make sure, as in this case, that animals are tested if there has been potential exposure (e.g. a bite).
• Make sure your pets are vaccinated against rabies.
• Keep your cats indoors. Mr. Duggan is lucky his cat wasn't exposed to rabies or killed by the rabid fox.
• Don't trust foxes that knock on doors.

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

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A dog park was closed because of an attempt by a dog-owner to disinfect puddles.  The woman was seen pouring a gallon of bleach into a mud puddle, sparking an investigation. The site was closed while city staff pumped out puddles. The woman told the person that witnessed and reported the incident that her dog had contracted the intestinal parasite Giardia in the park, and she was trying to sanitize the water.  However, authorities believe it may in fact have been a malicious act (i.e. an attempt to poison the dogs using the park).

• Firstly, there's no way the woman could know that the park (let alone a specific puddle) was the source of her dog's infection. Giardia can be found in the environment and in the stool of a small  percentage of healthy dogs (~7% in many studies).
• Secondly, pouring a toxic substance into the puddles in the park is obviously not an appropriate response. Bleach is a good disinfectant when it's used right, but disinfecting outdoor surfaces like this is essentially impossible. Organic debris (e.g. mud) will readily inactivate bleach, but the bleach could still make an animal sick if too much (too high a concentration) is swallowed, because it's very caustic.
• Thirdly, for this woman to take matters into her own hands like this without consulting  someone who knows something about infectious diseases, and potentially exposing a lot of animals to high levels of bleach is irresponsible. If there was concern about the park as a source of infection, the appropriate response would have been to talk to city staff.

In reality, the risk to other dogs was probably pretty low. It’s pretty obvious when there's a lot of bleach somewhere (even just based on the smell), and in general dogs would probably be very reluctant to drink bleach-contaminated water.

One officer stated that he suspects the Giardia story was an excuse contrived by the woman when confronted by the passer-by who witnessed the bleaching incident. That’s certainly possible, but I’m surprised someone would come up with a specific excuse like Giardia.  If the woman is found, that should be easy to figure out - the diagnosis would have to be in her dog's medical record.  Police stated that the woman, if identified by the authorities, could potentially face animal cruelty charges. I think that’s pretty unlikely, considering what usually has to happen for someone to actually be charged and convicted of animal cruelty. I suspect this really was an overzealous response by someone who lacks common sense. There was no comment about whether the woman would be billed for the city staff time required to deal with the clean up - that might be a more effective deterrent to similar incidents in the future!

Parks are inherently a high-risk environment for exposure to infectious diseases. Whenever you mix large numbers of animals, especially in an area where they often pass stool, there is an increased risk of disease transmission. You have to accept that when going to a park. People should also ensure that they never take a sick animal to a park, promptly clean up stool, and may sure that their pet is on an appropriate vaccination and deworming program. Disinfection of a park will never be part of the infection control program.

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

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A large outbreak of rabies continues to have devastating effects in Angola, Africa. While rabies outbreaks are not uncommon in some parts of the world, the number of people affected in this outbreak is remarkable. A hospital in Luanda, the nation's capital, has diagnosed rabies in at least 93 children in the past 3 months. All have died. The main source of the disease in this case is Angola's large stray dog population. Stray dogs can transmit rabies to other dogs and people through bites. The poor socioeconomic status of the country increases the risk of outbreaks like this because:

• Vaccines are not readily available (for dogs or people)
• It is difficult to organize and fund vaccination programs for stray dogs
• It is difficult to educate the general population about how to avoid and manage rabies exposure
• The healthcare system is relatively limited

These problems, all related to a poor economy, create a "perfect storm" for a rabies outbreak. The shortage of human rabies vaccine and the high cost of post-exposure prophylaxis (PEP) makes it much more likely that people will actually develop signs of rabies after being exposed. The cost of PEP is more than the average Luanda family makes in a month.

Fortunately, the outbreak seems to be waning. However, without improvements in stray dog management (including vaccination) and access to adequate PEP, future outbreaks and problems are inevitable. It was reported that "adequate" supplies of canine rabies vaccine are now available. Hopefully, a concerted effort to vaccinate as many dogs as possible will reduce the rabies load in the canine population, thereby helping to decrease the risk to the people living in the area as well.

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Rabies clinics are common in some areas. They are typically one or two day events where people can get their pets vaccinated against rabies at very low cost. The good aspect of these clinics is that some animals that get vaccinated there would not otherwise be vaccinated. The downside of rabies clinics is that they are not the same thing as a normal vaccine appointment with a veterinarian. Rabies clinics are usually "assembly line" vaccination - the goal is to get as many animals vaccinated as quickly and efficiently as possible.  The animals are not given a physical examination and there is no discussion with owners about preventive medicine or other problems. Therefore, there is no opportunity to detect and address other health problems, which is (in my opinion) the most important aspect of routine vaccination appointments. There is also no opportunity for vaccination against other important diseases. 

Rabies vaccine clinics can be beneficial in situations where some people are unable (or, unfortunately, unwilling) to pay for a normal veterinary examination and complete vaccination. Anything that increases the number of animals vaccinated against this devastating disease is useful. However, rabies clinics also can compromise the health of animals (and potentially their owners) if they are the only routine veterinary contact. They can also end up hurting owners financially in situations where early disease would have been detected and addressed during a regular vaccine appointment. Often, diseases are much more difficult and expensive to treat when they are identified later.

So, while it's obviously tempting to take the cheapest option available, if you can afford a regular veterinary appointment, don't use rabies vaccine clinics. It will be better for your pet and for you to have a regular vaccination appointment with a good physical examination and full consultation.

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

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Most pharmaceutical products are dosed on the basis of weight (e.g. milligrams of drug per kilogram of body weight). That means an animal twice the size of another gets twice the dose.

Other drugs (mainly chemotherapeutic drugs, like those used for cancer treatment) are dosed based on body surface area (e.g. milligrams of drug per square metre of body surface). With this type of dosing, large individuals get more than small individuals, but the differences are not as great as with weight-based dosing.

Vaccines are a different story. They are administered based on the "antigenic dose" which is independent of body size.  Therefore, the same dose is required for an adult Bullmastiff and a young Chihuahua. While it may be tempting to split doses of vaccine between several animals, especially small breeds (and initially this may seem logical (based on their small size) to those who do not realize how the dose is determined), this may result in ineffective vaccination. Trying to save money by splitting vaccine doses can end up costing money through increased risk of disease.  Always give the full dose of vaccine as described on the label.

This post originally appeared (in modified form) on www.equIDblog.com on January 4, 2009.

 

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Life is not risk-free. We shouldn't stop doing beneficial things just because of potential (and rare) side-effects, particularly when the benefits in most cases far outweigh the risks.

A recent article in the Cleveland Examiner discussed feline distemper (panleukopenia) vaccination. The author related the story of a cat that apparently had a "bad" (undescribed) reaction to the vaccine, which is certainly possible. Adverse reactions to vaccines are rare, but they certainly can (and do) occur. It's important that we don't react excessively to these highly unfortunate reactions, and end up in a situation where more animals get sick and die from the disease because people get scared of vaccinating against it. (The increasing rates of measles in people in some areas, including serious outcomes, following ill-informed paranoia of an association between vaccination and autism is a great human example of that).

The author goes on to state:

"What should you do to guard your cat against feline distemper? Ask a holistic practitioner for nosodes instead of a vaccine serum."  But there is no evidence whatsover that nosodes have any effect. A cat "vaccinated" with a nosode is an unvaccinated cat.

"The diluted formula is safe—it contains no live pathogens-- and effective." It's probably safe, but in no way effective.

"A cat who doesn’t mingle with other animals probably doesn’t need a vaccine against viruses." Bad advice. You'd be amazed by the number of 'indoor cats' that are taken to vet clinics after being hit by a car, getting in a fight with a stray cat, or similar non-indoor encounters. Close contact with strays can also occur through screen doors and windows. Then there's the issue of rabies exposure from bats in houses.  Altogether, avoiding vaccination of indoor cats will probably get the majority of cats in more trouble, not less!

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Back in the 1980s, Vietnamese Pot-Bellied Pigs were a popular fad pet.  These stout little oinkers are still out there, though they're not quite as popular as they once were.  Potbellied pigs are cute (at least to some people... to each their own!), supposedly quite smart, and can even be house trained/litter trained.  As with any new pet though, it's very important to do your research before going hog-wild and getting yourself a pot-bellied pig.  Talk to your veterinarian about what your pig will need in terms of medical care - vaccines, deworming, spay/neuter, hoof trimming, tusk trimming... Because they are uncommon pets, some veterinarians may not be comfortable treating a pig.  Make sure you ask ahead of time so you know to which veterinarian(s) in your area you can (and will!) take your pig.

We recently received a question about vaccination of pot-bellied pigs.  Just like dogs, in some areas pigs need to be licensed by the city, and certain vaccines are required in order to obtain a license.  In this particular case, pigs are required to be vaccinated against rabies, swine erysipelas and leptospirosis.  Regular visitors to this site are no doubt familiar with the issues around rabies and why it's important to vaccinate for this deadly disease.  (More information about rabies is available on the Worms & Germs Resources page and in our archives.)  Swine erysipelas is a systemic bacterial infection caused by Erysipelothrix rhusiopathia, which can rarely cause a skin infection known as erysipeloid in humans.  This is not to be confused with human erysipelas, which is a skin infection caused by various species of Streptococcus (particularly Streptococcus pyogenes). 

But the question was about leptospirosis vaccination in pot-bellied pigs.  Pigs are susceptible to infection by Leptospira interrogans, just like dogs and people, and if infected a pet pig would be equally capable of shedding the bacterium in its urine and potentially transmitting the disease.  The issues around requiring vaccination of pigs for leptospirosis are very similar to those around making leptospirosis a "core" vaccine in dogs.  More information about this is available in the Worms & Germs post entitled "Should all dogs in Ontario be vaccinated for leptospirosis?"  A pet pig would likely be exposed to the same serovars of Leptospira as a dog kept in the same area, typically by coming in contact with urine from infected wild animals such as raccoons and skunks when they go outside.  However, the risk of exposure for a pig that rarely or never leaves the house would be extremely low compared to a pig that has outdoor access.  Another important consideration is whether or not the pig vaccine is against the same serovars that a pet pig, instead of a commercial pig, might encounter.  This will also vary depending on in what area the pig lives.  The Leptospira servoars pomona and bratislava are actually host-adapted to pigs.

It is also important to vaccinate an animal with vaccines that are labeled for use in its own species.  Vaccinating a pig with a vaccine meant for dogs could have unpredictable results - it may increase the risk of an adverse reaction, or it may not adequately stimulate an immune response, thereby leaving the pig essentially unvaccinated.  Your veterinarian can discuss the pros and cons of vaccination in your pet with the available vaccine products.

More information about leptospirosis is also available on the Worms & Germs Resources page.

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In some areas, pet vaccines are readily available from multiple sources, including the internet. Some people like to purchase vaccines and administer them to their pets themselves in order to save money. But are the cost savings really worth the risk? Here are some things to consider:

• Your veterinarian gets vaccines through a reputable distribution system, which ensures quality control, tracking of products and proper shipping and storage conditions. When buying elsewhere (especially the internet), you don't have the same level of assurance. Vaccines that have been improperly handled or stored may not be effective.
• Vaccines and drugs from some sources are of questionable quality, and you can't always be sure that you're actually getting what you wanted. Ineffective vaccines or contaminated products are a big concern. It's not saving you money if the vaccine doesn't work!
• While uncommon, vaccine reactions do occur. If your pet has an anaphylactic (severe allergic) reaction at a veterinary clinic, the chances that your pet will survive are much greater because the needed expertise, drugs and equipment are readily available. You don't have these things at your house.
• If your pet develops a problem associated with a vaccine administered by your veterinarian, the vaccine manufacturer may get involved and assist with the problem. This will NOT happen if you buy the vaccine from another source and give it yourself.
• Rabies vaccines MUST be given by a veterinarian. (In some areas it's illegal for a non-veterinarian to even possess rabies vaccine.)  A pet that has received a rabies vaccine by a non-veterinarian is considered unvaccinated by public health authorities.  If an unvaccinated animal is exposed to rabies, the repercussions may be much more severe, and may even include euthanasia.
• Vaccination is just one part of your pet's "wellness program." Some of the pressure for people to vaccinate their own pets is a failure of the veterinary profession to adequately emphasize the importance of preventive medicine, of which vaccines are just one component. Simply charging an owner for "annual vaccines" leads people to want to vaccinate their pets themselves because they can get the vaccines for much less money.  Veterinarians need to emphasize that what they are charging for (and what is the most important component of the preventative medicine program) is an annual physical examination and health consultation, and that only a small portion of the fee is for the vaccines.

Vaccination is a minor component of your pet's preventive medicine program. A careful physical examination and consultation about potential, developing and ongoing health issues are the most important parts of this program. Even if you vaccinate your pet yourself (which is still not recommended for the reasons above), it is still critical that your pet has an annual examination. It's better for your pet's health, and it can be easier and cheaper in the long run because problems can be detected and treated early.

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A horse in Ontario was recently diagnosed with Eastern Equine Encephalitis (EEE), a serious neurological disease caused by a virus of the same name, which is transmitted by mosquitoes.  The horse was from the North Durham region.  The last reported cases of EEE in Ontario were in 2004.  A few weeks ago, the Worms & Germs Blog talked about a large number of cases of EEE that have been reported in Florida this year.

Here are some of the key points to remember about EEE:

• Like West Nile, EEE is a seasonal disease.  It is more common in warmer areas, especially some regions of the southeastern US.  It is rare in cooler climates, but occasionally EEE is found in horses in Ontario.
• EEE is usually fatal in horses, and there is no effective treatment.
• EEE can also occur in people, and can be fatal in some cases.
• Infected horses cannot transmit the EEE virus to people, but if a horse gets EEE from the mosquitoes in the area, then people could also potentially be exposed to the virus by mosquitoes.
• A vaccine for EEE is available for horses, but most horses in Ontario are not vaccinated for EEE because it is so rare.  Nonetheless, vaccination can be considered because the disease is so devastating when it occurs.
• As for West Nile virus, avoiding mosquitoes - for both horses and people - is an important preventative measure for EEE.

For more information, see the Worms & Germs Blog post "Eastern Equine Encephalitis – Not Just For Horses", or the CDC's website on arboviral encephalitides.

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In Ontario, and many other regions, mid-August is the beginning of the high risk period for West Nile virus infection in people and animals such as horses. The Ontario Veterinary College has published an informational video on YouTube. This video has information about measures you can take to reduce the risk of West Nile virus exposure and disease, for both people and horses. Click on the image to watch the video.  More information about West Nile virus is also available in the blog post entitled West Nile virus in dogs and cats.

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From Guest Author Dr. John Prescott, Professor, Department of Pathobiology, University of Guelph.  More information about Leptospira and leptospirosis can be found on our Resources page.

The last decade has witnessed a surge in leptospirosis in dogs throughout much of North America. Ontario and Québec have been part of the surge, which is associated with two serovars of Leptospira, grippotyphosa and pomona.

The reasons for the dramatic increase relate to: 1. The apparent spread of infection in raccoons and to a lesser extent skunks; 2. A changing climate that favours prolonged survival of these bacteria outdoors in the milder fall temperatures; 3. Perhaps to a minor extent increased awareness of the disease by veterinarians. Gillian Alton, a Masters student at the University of Guelph, has shown that the increased infection rate observed in recent years appears to have leveled off, which may be the result of widespread vaccination.

Leptospirosis should be suspected whenever there is kidney or liver inflammation of unknown origin, particularly in the fall of the year. In 2007, there were about 80 positive and 170 suspicious cases in Ontario based on blood tests submitted to the Animal Health Laboratory (AHL), University of Guelph. Since not all such blood tests go through the AHL, it is likely that there would have been about 160 positive and 350 suspicious cases based on this testing throughout Ontario, and an unknown number of cases diagnosed by PCR (a DNA-based test). If one includes cases diagnosed based on clinical signs but without laboratory testing, and about half the suspicious cases as positive cases, then there may be about 400 clinical cases (i.e. cases where the animal actually gets sick) of leptospirosis in dogs occurring annually in Ontario. Clinical leptospirosis in dogs is a serious disease and this number, if the assumptions are correct, represents a high burden of infection.

Arguments for recommending the new 4-way leptospiral vaccines as a “core” vaccine (i.e. all dogs should be vaccinated) in Ontario are:

1. The suggested size of the problem;
   
2. The often serious nature of the disease;
3. The zoonotic potential of the infection (a small number of human infections acquired from dogs have been recognized in Ontario and Québec in recent years);
4. The ongoing widespread presence and sometimes large numbers of raccoons in suburban and urban Ontario;
5. The diagnosis of canine leptospirosis throughout the province;
6. The diagnosis of the disease in dogs of all types, not just the “male hunting dog” which is sometimes conventionally regarded as “high risk”.

Arguments against recommending the new 4-way vaccines as a “core” vaccine are:

1. The sporadic nature of the infection, including the lack of exposure of some dogs to raccoons and other wildlife sources;
2. The number of vaccine reactions associated with leptospiral vaccines (this is not a significant problem with at least one of the vaccines);
3. The considerable confusion caused by the (almost certainly totally unfounded) suspicion that serovar autumnalis causes canine leptospirosis, but is not in the new vaccines;
4. The lack of inclusion of serovar bratislava in the vaccine (although this serovar seems to cause only mild disease in dogs);
5. The annual cost of revaccination.

The vaccine manufacturers have the responsibility to provide the supporting data on which a “core vaccine” recommendation should be based, by testing dogs in Ontario for exposure to the different serovars. In the absence of such data, but knowing the possible extent of the problem, veterinarians should always discuss the pros and cons of leptospiral vaccination with dog owners. My opinion is that, barring problems of vaccine reactions and hypersensitivity in individual dogs, annual leptospiral vaccination with a 4-way vaccine should be recommended.

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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.

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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. 

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A recent issue of CDC’s Morbidity and Mortality Weekly Report described a case of rabies in a person from Minnesota. This person died of rabies in 2007. Approximately one month before he became ill, he held a bat in his hands and felt a ‘pin-prick’. He didn’t see a wound or blood and assumed that he had not been bitten. Since neither he nor his family knew that this type of contact was actually considered rabies exposure, he did not seek medical attention. He died approximately 3 weeks after he developed rabies. Post-exposure rabies treatment would have almost certainly prevented his death.

- Never handle a bat
- Assume all bats are rabid until proven otherwise
- Any contact with a bat is considered to be rabies exposure unless the bat has been tested and shown to be negative. All bat exposures should be reported to the appropriate public health authorities.
- Despite all the old stories, rabies exposure treatment is not horrible…it’s just a series of shots in the arm.
- Vaccinate your pets. You never know when they’ll encounter a bat…inside or out.

More information on rabies is available in our Resources area.

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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.

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