Q. Can West Nile virus (WNV) cause illness in dogs or cats?
A. A relatively small number of WNV infected dogs (<40) and only 1 WNV infected cat have been reported to CDC during 2003. Experimentally infected dogs* showed no symptoms after infection with WNV. Some infected cats exhibited mild, nonspecific symptoms during the first week after infection--for the most part only showing a slight fever and slight lethargy.
It is unlikely that most pet owners would notice any unusual symptoms or behavior in cats or dogs that become infected with WNV.
Q. Does my dog/cat becoming infected pose a risk to the health of my family or other animals?
A. There is no documented evidence of dog or cat-to-person transmission of West Nile virus. The evidence suggests that dogs do not develop enough virus in their bloodstream to infect more mosquitoes. Cats develop slightly higher levels of virus in their bloodstream, but it is unclear if this would be enough to infect mosquitoes. It is very unlikely that cats would be important in furthering the spread of the virus.
*If your animal becomes infected with WNV, this suggests that there are infected mosquitoes in your area. You should take measures to prevent mosquitoes from biting you (use repellent and wear protective clothing.)
Veterinarians should take normal infection control precautions when caring for any animal (Including birds) suspected to have this or any viral infection.
Q. Can I use insect repellent on my pets?
A. DEET-based repellents, which are recommended for humans, are not approved for veterinary use (largely because animals tend to ingest them by licking.) Talk with your veterinarian for advice about the appropriate product for use on your pet.