West Nile virus does not usually cause illness in dogs and cats and there is no evidence that a dog or cat can transmit the virus to humans or other animals, horses are however more susceptible to West Nile virus and closely related viruses but fortunately, there is an effective West Nile virus vaccine for horses.

To date the West Nile virus has been detected in 35 mammal species including domestic cattle, reindeer, harbor seal, little brown bat, rhesus macaque, Asian elephant and gray squirrel - the virus has also been identified in two reptile species, American alligators and crocodile monitors.
 

Although other birds can become infected with the West Nile virus, the mortality rate is much higher in crows than in other birds - in the crow family crows, jays, ravens, and magpies, tend to become sick and die - and crows' susceptibility to the virus makes them very useful sentinels in monitoring viral activity.

While there is no evidence that a person can contract the virus from handling live or dead infected birds, experts recommend that it is always best to avoid barehanded contact when handling any dead bird or animal - for disposal, they advise the wearing of gloves and the careful placing of the bird in double-plastic bags.

Local health department officials will assist with specific instructions for storage if the dead bird is suitable for testing.

Though West Nile virus is NOT transmitted from person-to-person, some evidence exists that crow-to-crow transmission is possible without mosquito vectors.