Initially, the dog flu virus was identified in racing greyhounds, and it was thought that the virus was exclusive to this breed. However, the disease has now been confirmed in the domestic dog populations in Florida, New York, and Massachusetts. Common symptoms include cough, nasal discharge, and fever. These symptoms usually resolve over time with appropriate treatment.
Influenza A viruses have infected many different animals, including:
However, some subtypes of influenza A viruses are specific to certain species, except for birds, which are hosts to all known subtypes of influenza A. Influenza A viruses normally seen in one species sometimes can cross over and cause illness in another species.
For example, until 1998, only H1N1 viruses circulated widely in the U.S. pig population. However, in 1998, H3N2 viruses from humans were introduced into the pig population and caused widespread disease among pigs. Most recently, H3N8 viruses from horses have crossed over and caused outbreaks in dogs. This is known as dog flu or canine flu.
Initially, the dog flu virus was identified in racing greyhounds, and there was some speculation that the virus was exclusively causing disease in this breed. However, dog flu has now been confirmed in the domestic dog population, first in the state of Florida, and then in other states.
Symptoms of Dog Flu
Dogs can become infected with the dog flu virus and show no apparent symptoms. This is called a subclinical or inapparent infection. In other cases, symptoms can be severe. The virus can cause a respiratory disease that mimics a syndrome called kennel cough.
Common symptoms of dog flu include:
- Nasal discharge
About 80 percent of dogs with the disease will have a mild form, characterized by cough and maybe some nasal discharge, which will resolve over time with appropriate treatment. Only a minority of dogs experience more severe complications, such as pneumonia. Just like humans infected with influenza, certain populations of dogs are more likely to develop complications. Death is a rare complication of dog flu.