Can Dogs Get West Nile Virus?

Stephanie Dube Dwilson

West Nile virus (WNV) first appeared in North America in 1999. Spread by infected mosquitoes, the virus often creates either no symptoms or mild symptoms that last several days to several weeks. However, if it enters the brain, it can be much more severe. Can dogs get West Nile virus? As a pet owner, you're no doubt worried about your pup's health—and not just your own. Although rare, it's indeed possible for dogs to get West Nile virus. But you can take steps to protect your dog from danger.

How West Nile Virus Infects Dogs

Dogs can get West Nile virus from mosquitoes, just like people do. The virus resides inside mosquito's salivary glands. The mosquito transfers the virus when it feeds on the blood of your dog, cat, horse—or even you. Mosquitoes are by far the most common transmitters of WNV to humans or their companion animals.

Mosquitoes become infected after feeding on wild birds that carry the virus, then they transmit it through bites to people, animals, and other birds.1

The good news is that WNV doesn't transfer directly from pet to pet or from pet to human.2 (The only exception is emus, which may spread the virus to animals or humans.) Although some laboratory experiments show cats and dogs can acquire the disease by eating infected birds, no transmissions of this type of have been documented by health authorities.3

West Nile Virus Symptoms in Dogs

West Nile virus tends to be mild unless the disease enters the brain, where it can cause encephalitis. Encephalitis can be debilitating or fatal in a small portion of infected people and animals. The good news is that although the virus can infect dogs, they don't seem to easily develop active infections. This is in contrast to horses, humans, and some bird species, which are much more likely to develop active West Nile virus infections. Horses are especially susceptible and may suffer serious neurological effects that can be permanent.4

For animals of any sort, the young, the old, and immune-compromised are most likely to have complications of West Nile virus.5 The symptoms of West Nile virus in dogs include depression, decreased appetite, difficulty walking, circling, seizures, muscle weakness, spasms, and fever. If you suspect that your pet may be infected, see your veterinarian. Your vet will treat an infected dog as they would any viral infection—by relieving the symptoms.

Protecting Your Dog from West Nile Virus

There's no West Nile virus vaccine for humans or dogs. (However, vaccines are available for horses.) So your best move is to prevent an infection in the first place. You can protect your dog from West Nile virus by protecting your dog from mosquitoes. Here's how:

  • Eliminate mosquito breeding sites, including overgrown grass and weeds, as well as standing water. Even a flower pot, soda can, or coffee cup partially filled with rainwater can breed mosquitoes.
  • Install or repair screens on windows and doors to keep mosquitoes outside.
  • Use mosquito repellents made for dogs to boost protection when outside. Many flea and tick treatments for dogs work on mosquitoes too. One example is Adams Plus Flea & Tick Prevention Spot On for Dogs, a spot-on treatment you can put on your dog that both repels and kills mosquitoes. Or consider Adams Flea & Tick Collar for Dogs and Puppies, which repels mosquitoes* for up to six months per collar.
  • Treat your yard with Adams Yard & Garden Spray to kill mosquitoes in your lawn, trees, shrubs, roses, and flowers.
  • Protect your home from mosquitoes that may carry WNV with Adams Plus Flea & Tick Indoor Fogger, which kills fleas, cockroaches, ants, spiders, mosquitoes, silverfish, and many other insects.
  • Remember that mosquitoes are most active from dusk to dawn. Limit your pup's outside time to bright sunny periods to reduce your pet's risks of suffering mosquito bites.

Although West Nile virus can be serious on rare occasions, it's easy to prevent. Simply protect your dog from mosquitoes, and you'll protect him from West Nile too.

*excluding California.

1. Washington State Department of Health. "West Nile Virus. 2020 West Nile Virus Activity." DOH.Wa.Gov,

2. "WNV and EEE in Animals.",

3. USGS. "Can My Dog or Cat Get West Nile Virus by Eating an Infected Animal?",

4. "West Nile Virus in Domestic Animals and Birds.",

5. Okaw Veterinary Clinic. "West Nile Virus in Pets.",

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