It is possible for dogs and/or cats to become infected with West Nile virus by being bitten by a mosquito carrying the virus. A relatively small number of West Nile virus infected dogs and cats have been reported to the Center for Disease Control. In fact, experimentally infected dogs show no symptoms after infection with West Nile virus. Some infected cats showed mild, nonspecific symptoms during the first week of infection; usually only a slight fever and lethargy.
Because most pets show no to minimal signs, there is no specific treatment for West Nile virus infection in dogs and cats, and full recovery is expected. There is no documented evidence of dog or cat to person transmission of West Nile Virus. The best prevention is to practice good mosquito control, including using topical products like K-9 Advantix (for dogs only) or topical Revolution in dogs and cats.