This page produced by the Continuing Education-Public Service/Extension group at the University of Illinois College of Veterinary Medicine in Urbana.
Go to the College West Nile Virus page.
Q: Can West Nile virus (WNV) infect dogs and cats?
A: Yes, however infection rates in epidemic areas are low. WNV does not
usually cause severe illness.
Q: Which dogs and cats are likely to be the most susceptible?
A: Based on the most recent animal cases seen at the University of
Illinois College of Veterinary Medicine
Veterinary Diagnostic Laboratory, young, old, and immune-compromised pets
would seem to be at a higher risk.
Q: How do dogs and cats become infected with West Nile virus?
A: The same way humans become infected: by the bite of infectious
mosquitoes. It is possible that dogs and cats could become infected by eating
dead infected animals such as birds, but this is unproven.
Q: What advice should I give to my clients to protect their pet dog
or cat?
A:
Q: Is there a mosquito repellent available that is safe to use in
dogs?
A: Yes. There are a few products that are approved for safe use in dogs.
Products may be available at local pet stores/feedstores or veterinary offices.
We have recommend pet owner to contact their veterinarian regarding the use of
these products.
According to the most recent Veterinary PDR®, the following products have been
approved for use in dogs to prevent or repel mosquitoes. (Note: several of these
are horse products that are also approved for use in dogs.)
In addition, applying a pyrethrin-based flea spray in accordance with the label directions for that species may be the safest method to try to repel mosquitoes on pets. Reapplication of the spray may be necessary for animals that will spend much time outdoors.
Q: Is it safe to use a mosquito insect repellent meant for humans
on pets or to use a product containing DEET(N,N-diethyl-m-toluamide,
N,N-diethyl-3-methylbenzamide)?
A: No, only approved mosquito repellents should be used on pets. Clients
should be told to read the label first to determine if the product is approved
for use in pets and then follow label instructions for applications. Topically
applied DEET may be absorbed dermally as well as orally when pets groom
themselves, increasing exposure and the potential for problems. The use of DEET
on animals is not recommended and should be avoided. DEET has been associated
with serious adverse effects when used on dogs and cats. Citrus oil extracts and
other essential oils are also not recommended due to the extreme sensitivity of
some animals to these products.
Q: What are the signs of WNV in dogs?
A: Neurological signs that are similar to those seen in horses, such as
incoordination, depression, decreased appetite, difficulty walking, tremors,
abnormal head posture, circling, and convulsions. These signs can mimic other
diseases (especially distemper, rabies, and brain neoplasia) therefore it is
very important to consider these as well.
Q: Is there a vaccine available for pets?
A: No, the only vaccine currently available is for horses.
Q: What is the treatment for WNV in pets?
A: Treatment is supportive and consistent with standard veterinary
practices for animals infected with a viral agent.
Q: Can pets transmit the WNV to humans or other pets?
A: There is no documented evidence that animal-to-animal or
animal-to-person transmission can occur. There is no reason to destroy an animal
because it has been infected with WNV.
Q: If I suspect a patient may have WNV based on clinical signs, is
an ante-mortem test available?
A: Currently, there are only a few laboratories that will accept samples
from dogs and then only if they are clinically ill. National Veterinary Services
Laboratories (NVSL) is one of those laboratories. Please note that NVSL is
inundated with sera from sick horses all around the country and is not
establishing a high priority on the dog sera. Therefore, veterinarians will
likely not get results from NVSL on dogs for several weeks. By that time, the
dog will either have recovered or, in the unlikely case, died. Also the serology
test for dogs measures IgG which may last for years, therefore, positive
serology results for WNV on canine serum may not indicate recent infection.
The New York State Animal Health Diagnostic Laboratory will also accept samples for serology, PCR testing of blood and virus isolation. The laboratory should be contacted before submitting specimens to ensure proper packaging and submission, to ensure that they are currently receiving out-of-state specimens, advice on how to interpret the serology results and to obtain current fee information.
Q: Is there a way to diagnose WNV post-mortem?
A: If death occurs, the diagnosis of WNV may be established through
post-mortem examination and examination of the brain and other tissues by
histology and immunohistochemistry (IHC). Contact your diagnostic laboratory
regarding specific information on submitting post-mortem samples for these
tests. Currently in Illinois both the Galesburg and the U of Illinois diagnostic
laboratories are performing the IHC test.
Q: Do I need to contact anyone if I suspect that an animal has West
Nile Virus?
A: Yes, West Nile Virus is a reportable disease in the state of Illinois.
Therefore, you must contact the Illinois Department of Agriculture at
217/782-4944 to report a suspected or confirmed case of West Nile Virus
in any animal.
Created September 19, 2002; last modified April 08, 2003, by DFD; prepared by Dr. Christine Merle, Small Animal Extension Veterinarian, University of Illinois College of Veterinary Medicine, Continuing Education and Public Service Unit/Extension.