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.)
Vet-Kem Triple Action Flea & Tick Shampoo for Dogs, Cats, & Horses
K9 Advantix by Bayer was recently approved for the killing and repellancy
of mosquitoes in dogs. This product is available only through veterinarians.
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.