Cats, Bats, and Rabies

Awhile back, one of our client's cat brought home a bat, and she called me asking what they should do with the bat and if they should be worried about rabies. The cat, bat, and children were all in the back yard together, and whether or not the children touched the bat was unlikely, but uncertain. We get asked these questions often enough that I decided to write a post about cats, bats, and rabies and try to address these questions to the best of my ability.

1. What should you do if your pet catches a bat?
DO NOT touch the bat barehanded! This is very important. Put on thick leather gloves and put the bat in a container that can be disposed of. If you think any person may have been exposed to the bat --touched or bitten -- phone your county Health Department and tell them the situation, then phone your physician as well. If only your pet has been exposed to the bat, phone your veterinarian. The bat will need to be sent in to a laboratory for rabies testing. Most public health departments will send the bat off for testing (for free) if a human has been exposed, but not if only your pet has been exposed. If your pet has been exposed, the bat should still be sent off, but at your expense (around $40). It is important to know if the bat is infected with rabies or not.

2. What should you do if you simply find a bat laying in your yard or in your house in broad daylight?
The same applies as above. DO NOT touch it with your bare hands. If it is outside, just let it be and see if after 10 minutes or so it has gone elsewhere. The problem lies in the fact that most bats that are found in broad daylight are ill, and some of them may be ill with rabies. If the bat is still there and you have children or animals, it is best to dispose of the bat as indicated above. You may want to call your veterinarian or public health official first.

3. What is the big deal with rabies anyway?
Rabies is a virus that is spread via saliva from the bite of a rabid animal. The virus travels through the nervous system, and once it reaches the brain it is deadly. The incubation period for rabies is quite variable among mammals and depends partly on how far the virus has to travel before it reaches the brain. So for example, if a rabid dog bit your face or a bat bit your cat's face, the virus wouldn't have very far to travel before it reached the brain. However, if you were bitten on the toe, the virus would have a long way to travel via the peripheral nerves to the brain. Incubation periods in dogs and cats range from 2 weeks to 6 months (but average 3-6 weeks). In the U.S. rabies is not the huge problem that it is in many parts of the world, but still-- infection with rabies without treatment is deadly --that's the BIG deal.

Image of dog with "furious" rabies

4. What animals can carry rabies?
Any warm-blooded animal can be infected with the rabies virus and thus spread it. In our area of the country we have no terrestrial rabies -- that is to say, no animals that live on the ground are endemic for rabies. In the northwest, our primary source of rabies is bats, and the rabies viruses isolated from infected terrestrial animals have all been found to have originated from bats. In the southwest and mid-west the main sources of rabies is skunk and fox, and in the east and northeast the main source is raccoons.

5. What are the symptoms you might see if your pet was infected with rabies?
The first stage of the disease is the "prodromal phase". In this phase your pet may show anxiety, nervousness, or apprehension and may do a lot of hiding. A fever may be noted especially in cats. Your pet may be irritable and try to bite, or it may be docile and friendly if it is normally aggressive. The second stage is the "furious phase". In this phase your pet may be hypersensitive to auditory and visual stimuli, may become restless and roam more, and may be irritable and vicious. The final stage is the "dumb or paralytic phase". In this phase the nerves that go the head and throat are affected causing the jaw to drop and the animal to be unable to swallow -- thus the stereotypical drooling and foaming. The animal may be thirsty but unable to drink, that is why another term for rabies is hydrophobia. An animal may exhibit some or all of these symptoms. Death is inevitable once symptoms are observed. A VERY few people have survived, and there are anecdotal accounts of dogs surviving.

Image of dogs with "dumb" rabies

6. How is rabies diagnosed?
The only way that we have of diagnosing rabies at this point is submission of brain tissue for microscopic inspection, so unfortunately euthanasia is a must for diagnosis.

7. Are all bats infected with rabies?
No, not all bats are infected with rabies. In fact, only about 10% of bats that are submitted for rabies testing are positive. That means that the percentage of rabies positive bats in the wild is probably much less, because normally you wouldn't find a bat just hanging around where you or your pet could catch it unless it were sick (possibly with rabies). However, if it was me or my child, I would not play the guessing game. I would presume a bat was rabies positive until proven otherwise.

8. What is the best way to prevent rabies infection?
Vaccination. Vaccination of pets is the only way you can help to prevent your exposure to rabies. That and steering clear of any wild animals that are acting suspiciously. Dog and cat vaccination protocols are strictly regulated: First vaccine at or after 16 weeks followed by a booster at one year. Then another booster every three years (at least in our good state of Washington). You should have your cat and dog vaccinated for rabies even if it is strictly indoors, because bats can come into a house through the smallest opening. Also, if your dog were to ever bite a person (heaven forbid), up-to-date rabies vaccination will be important to help keep your pet from being euthanized. There are also a rabies vaccine for people -- veterinarians are required to be vaccinated against rabies since they may be more likely to come in contact with a rabid animal than the average person.


The bottom line is: Educate your children not to touch a bat if they (or their pet) finds one and vaccinate your pets against rabies. Just last year a young boy and his dog were found playing with a bat in northern Whitman County. Luckily someone found them and captured the bat for testing because the bat was found to be positive for rabies. The little boy had to go through prophylactic treatment for rabies infection and the unvaccinated dog was euthanized.

One more bottom line: If there is any doubt as to whether a human has been exposed to a bat bite, err on the side of caution. Another tragic story from Washington State occurred about 15 years ago when a bat was found in the room of a young girl who was sleeping. No bite wounds were found on the girl so no further medical attention was sought. Unfortunately, about a month later the little girl died from rabies. The bat was dug up from the backyard and was positive for rabies. So sad.


Here is a collection of helpful links where you can learn more about bats, rabies, and such.
Living with Bats
Journal of the American Veterinary Medical Association --Rabies Survey 2007
CDC- Bats and Rabies
Whitman County Department of Public Health

(images courtesy of http://www.vaccineinformation.org/rabies/photos.asp)

Parvo Virus

In the past month or so, we have treated several cases of puppy parvo in the clinic. It seems that we cannot stress enough how important it is to get your puppy or dog properly vaccinated against parvo virus. This very common disease can quickly turn a happy, healthy dog into a sick or dead dog in just a few hours to days. The virus and disease is described well at the following site: {Canine_parvovirus} Usually, the first signs we see with parvo viral infection can easily be mistaken for a simple upset gastrointestinal tract --a little vomiting and the dog no longer wanting to play. This is usually followed in a day or two by diarrhea, and then bloody diarrhea. Unless the dog is treated quickly, death from dehydration and electrolyte imbalance can occur quickly.

Parvo virus is everywhere, and I mean EVERYWHERE. It is a very sturdy virus -- only reliably killed with a strong bleach solution. It can last in the ground or on other surfaces for years. You never know where your puppy may come in contact with it, and of course puppies are always sniffing, licking, chewing anything they can find. Take your unvaccinated puppy to a friend's house where several years ago another dog have parvo diarrhea all over the yard and unbeknownst to you, you just infected your puppy with parvo.



It is the saddest thing when a puppy comes in and is deathly ill with parvo. Sad because in most cases, the illness and possible death could have been avoided if the owner had been correctly informed about vaccination. Often the owner is mistaken told by a breeder that the 6-8 week old puppy has been vaccinated twice already and needs no further vaccination. Or, the owner mistakenly assumes that since the puppy has been vaccinated at least once by the breeder, then it is up-to-date. This is just not true.

How the vaccination works is a little complicated, so hang in with me. Puppies are born with some maternal antibodies already running around in their blood, and then they receive more antibody protection through the colostrum they nurse from the mother dog in the first 24hrs post birth. This maternal antibody protection, against myriads of diseases, lasts anywhere from 6-10 weeks of age depending on many factors. A vaccine stimulates the body to make their own antibodies (not passive antibodies from the mother) and memory to make more antibodies when challenged by a virus or bacteria. So, for the vaccine to work, there must be very little of the maternal antibodies left in the puppy, and as the age for this varies greatly from puppy to puppy -- we are stuck doing sort of a crap shoot when it comes to vaccinating puppies. To try to make sure that every puppy is adequately vaccinated, we need to cover both ends of the spectrum. Some puppies may run out of maternal antibody by 6-7 weeks while others will still be protected until 10-11 weeks. accomplish this at 8-10 weeks. And since most vaccines need at least two doses to be fully effective, we need to start vaccinating around 6-8 weeks and continue with boosters every 3-4 weeks until 14-16 weeks. So, there it is-- it all comes down to immunology -- not money sucking veterinarians trying to make a buck. We especially don't like to see sick and dying puppies in the clinic when we know it could have been prevented.



A couple more thoughts on parvo. It makes me cringe to see young puppies taken out and about to parks, the river, and other public places. Knowing what you now know about parvo and immunology, it should make you cringe too. You really shouldn't feel safe taking a young puppy to a public area until it has had at least 2 (or better yet 3) vaccinations for parvo. Also, just because you have an old dog, don't think that you don't have to worry about parvo any longer. An old dog that has not been vaccinated in a few years can be just as susceptible to parvo as a young unvaccinated puppy -- an aging body and other illnesses can make the immune system not as strong. Oh, and one more thing -- we recommend getting your vaccines from your veterinarian because you just don't know how the vaccines from the catalogues or feed store have been handled and stored. Vaccines are temperature sensitive and cannot be sure they have been kept cool. Our vaccines come on ice overnight from sources we trust -- if they are warm, we send them back. No sense taking risks.

A couple of good sites to visit about parvo:

http://www.avma.org/animal_health/brochures/canine_parvo/parvo_brochure.asp
http://en.wikipedia.org/wiki/Canine_parvovirus

Rattlesnake Vaccine

Did you know that there is a vaccine for dogs against the venom of this bad boy? That's right! We live in an area where there are [Western Rattlesnakes (Crotalis viridis)]. In our clinic we have been recommending vaccination against rattlesnake venom for 4 years now. Part of our clientele and their dogs live in areas of the county that are particularly prone to rattlesnakes. Every summer we usually see half a dozen dogs come in with snake bite. Typically a dog that has been bitten by a rattlesnake comes in and is pretty ill --swelling, pain, lethargy, fever, and infection -- are all symptoms. Most dogs will survive a bite if treated soon and appropriately. The most dangerous bites are to the head and neck as swelling is a big concern. However, if the dog has been vaccinated for the rattlesnake venom, these symptoms are MUCH less severe -- there may be a little swelling and pain, but less.


We have been offering this vaccine from [Red Rock Biologics] and we like how well it works. The protocol for vaccination is a two dose vaccination a month apart to begin with, then yearly (usually in the late spring when the snake are about to come out). It takes 4-6 weeks for the initial dose to be effective. I should point out that once your dog is vaccinated, you should still bring the dog in to the veterinarian after a snake bite, but the urgency of treatment is not so immediate. The amount of venom that is released during a bite varies greatly, and sometimes the bite is "dry" -- or no venom is released. However, the fangs of the snake often harbor bacteria and the wounds from the bite will become infected, and with the disruption of cells that the venom can cause, the infection can be bad. Thus, we usually put a dog on antibiotic therapy to offset the possible infection.

There is some controversy on the Internet about the efficacy of the vaccine and whether or not it is even necessary. All I can say is that at our clinic, we have noticed that it does help. And our clients that have dogs that get bitten repeatedly summer after summer notice the difference too. We have not observed any bad reactions to the vaccine itself in any of the dogs we have vaccinated. We do not recommend that every dog get vaccinated, only the dogs that live in areas where rattlesnakes are common and the likelihood of getting bitten is high.

Links:
For information on the vaccine --
http://www.redrockbiologics.com/risks.html

For information about Western Rattlesnakes:
http://www1.dnr.wa.gov/nhp/refdesk/herp/html/4crvi.html