West Nile Virus in Dogs

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.

The good news is that WNV doesn’t transfer directly from pet to pet or
from pet to human. 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.

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.

For animals of any sort, the young, the old, and immune-compromised
are most likely to have complications of West Nile virus. 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.