The Virology Lab at Cornell isolated the first influenza virus from a dog that died from the infection. The virus was sequenced at the CDC as subtype H3N8 and was found to be closely related to equine influenza virus. Researchers at the CDC suspect that a change of 8 to 10 amino acids in the Hemagglutinin gene (the H in the H3N8) may be responsible for the ability of the virus to infect dogs.
The clinical signs of canine influenza virus infection closely resemble a common respiratory syndrome known as Kennel Cough, and may include nasal discharge, high fever and a soft gagging cough of 10-14 days. While some dogs can be infected with the virus and not show clinical signs, a small percentage will develop more severe complications such as pneumonia. Canine influenza virus is characterized as a high morbidity low mortality virus. The mortality rate for dogs suffering from complications associated with canine influenza infection is 1 to 5 percent. Canine influenza should be a differential diagnosis for any dog presenting with respiratory disease. No vaccine is currently available.
Rapid identification and isolation of suspected cases of canine influenza in veterinary clinics, shelters and boarding facilities are recommended.
Researchers have indicated that this influenza virus subtype has circulated in horses for over 40 years and has never infected humans. However, the CDC will be monitoring for human exposure to the virus.
The New Jersey Department of Agriculture Animal Health Diagnostic Laboratory can provide preliminary screening for canine influenza. Samples suspect or positive on this preliminary screen will be forwarded to the appropriate veterinary diagnostic laboratory for additional testing.
If you have a suspect case of canine influenza and would like to submit samples for preliminary screening, please call the New Jersey Department of Agriculture Diagnostic Laboratory at (609) 671-6400.