Margaret C. Barr, DVM, PhD

Historically, cats have been considered to be resistant to influenza virus infections.

Dogs, like cats, have generally been resistant to influenza infections. However, equine influenza virus was implicated in an outbreak of respiratory disease in racing greyhounds from Jacksonville, Fla., in early 2004.

Many researchers and health officials are concerned about the potential for an influenza pandemic caused by avian influenza virus.