Dogs
and Cats
According to the Centers for Disease Control and Prevention, West Nile virus does not appear to cause extensive illness in dogs or cats.
There is no documented evidence of person-to-person or animal-to-person transmission of West Nile virus. Because West Nile virus is transmitted by infectious mosquitoes, dogs or cats could be exposed to the virus in the same way humans become infected. Veterinarians should take normal infection control precautions when caring for an animal suspected to have this or any viral infection. It is possible that dogs and cats could become infected by eating dead infected animals such as birds, but this is undocumented.
There is a single published report of West Nile virus isolated from a dog in southern Africa (Botswana) in 1982. West Nile virus was isolated from a single dead cat in 1999. A serosurvey in New York City of dogs in the 1999 epidemic area indicated that dogs are frequently infected. Nonetheless, disease from West Nile virus infection in dogs has yet to be documented.
There is no reason to destroy an animal just because it has been infected with West Nile virus. Full recovery from the infection is likely. Treatment would be supportive and consistent with standard veterinary practices for animals infected with a viral agent.
Concerned pet owners should consult with their veterinarian if their pets are exhibiting any unusual symptoms.