- West Nile virus is usually transmitted to dogs and cats through the bite of an infected mosquito.
- Clinical signs of infection in dogs and cats may be very mild or absent.
- Protecting your pets from mosquitoes will reduce their risk of exposure to West Nile virus. Ask your veterinarian about safe and effective mosquito-repellant products for your pets.
What Is West Nile Virus?
West Nile virus (WNV)is a virus that causes encephalitis (brain inflammation). WNV is usually transmitted to dogs and cats through the bite of an infected mosquito. Some birds, including crows, jays, sparrows, finches, grackles, and robins, are competent reservoirs for the virus (meaning they are able to infect mosquitoes). Some infected birds can shed WNV in their feces and other body fluids. In theory, cats and dogs can become infected through ingestion of (or contact with) an infected bird, but mosquito bites remain the primary route of infection.
Currently, WNV is relatively uncommon in dogs or cats. Birds, horses, and humans are more likely to become infected. Although WNV occurs in people, transmission of the virus from dogs or cats to people has not been documented.
What Are the Signs of West Nile Virus in Pets?
Clinical signs in WNV-infected dogs and cats may include fever, lethargy (tiredness), and polyarthritis (joint inflammation). However, most infected dogs and cats do not display clinical signs, or signs may be very mild.
How Is West Nile Virus Diagnosed and Treated in Pets?
Blood tests are generally used to confirm a diagnosis of WNV in pets. Fortunately, most pets recover fully from the infection. Treatment of WNV is mostly supportive. Your veterinarian will show you how to manage any clinical signs until they disappear.
How Can I Protect My Pet From West Nile Virus?
Dogs and cats are usually infected with WNV through the bite of an infected mosquito. There is currently no vaccine against WNV for dogs and cats. Prevention focuses on reducing exposure to mosquitoes and using approved products that safely and effectively repel mosquitoes from dogs and cats.
The best ways for people to avoid being bitten by mosquitoes are to wear long-sleeved shirts, long pants, and socks outdoors; limit outdoor activities and take extra precautions during evening and early morning hours when mosquitoes are most active; and use an insect repellent that contains DEET. (Note: DEET-based repellents are not approved for use in dogs and cats). Talk with your veterinarian about safe and effective mosquito-repellant products to use on your pets.
To mosquito-proof your home, drain any standing water on the property and install or repair screens so mosquitoes cannot enter.