Overview
The canine influenza virus is a highly contagious, newly emerging pathogen in the dog population. The virus appears to have mutated from the equine influenza virus. Canine influenza virus infections can be mistaken for infections caused by Bordetella bacteria / Parainfluenza viruses, part of the traditional “kennel cough” complex.
When was canine influenza disease first identified?
Canine influenza was first identified in racing greyhounds in 2004. The virus appears to have been responsible for widespread respiratory disease affecting dog tracks throughout the USA for the last two to three years. Cornell University first isolated the influenza virus from an animal that died during one of these outbreaks. Evidence of infection of non-greyhounds has been found in Florida (as of May 2005) as part of ongoing research by Dr. Cynda Crawford (University of Florida). Veterinary clinics, boarding facilities and humane shelters have all experienced positive-testing cases. Confirmed cases are also now reported from New York State (New York City 2005). Testing of some ill dogs from other states such as Massachusetts has also produced positive tests to influenza virus, but widespread screening is still in the early phase.
Are all dogs at risk of contracting the canine influenza virus?
Yes, all dogs, regardless of breed or age, are susceptible to infection. They have no naturally acquired or vaccine-induced immunity. Virtually 100 per cent of exposed dogs become infected. Nearly 80 per cent of infected dogs will contract a form of the disease which will produce obvious signs of illness. Of these, a small percentage of dogs will experience more severe clinical progression, including pneumonia.
What is the fatality rate for dogs infected with the canine influenza virus?
Fatal cases of pneumonia have been documented. In those dogs where the cause of death was verified by diagnostic testing, reported death rates for dogs with pneumonia ranged from 1 to 8 percent. Some of the popular media outlets are reporting 10 percent death rates overall for infected/exposed dogs, but to date, this is not supported by clinical data.