The Animal Health Diagnostic Center at Cornell has reason to believe that canine influenza virus is now present in the New York City Area. Reports have been received indicating an unusual form of “kennel cough” has been seen in a number of veterinary practices. Six animals recovering from this suspected illness have tested positive for canine influenza virus. Previous tests of dogs from New York State have been negative. There have been previous outbreaks of disease associated with this virus in Florida and other states.
Dogs are susceptible to this virus and have no natural immunity. There is no vaccine available to prevent infection with the virus. Nearly 100% of exposed dogs become infected. Dogs ill with this virus present as one of two clinical syndromes – a mild syndrome or a more severe syndrome involving pneumonia.
Most dogs have the mild syndrome involving a cough that persists for 10 – 21 days despite treatment with antibiotics and cough suppressants. The cough may be soft and moist or it may be dry and sound similar to the cough heard with “kennel cough.” Mildly affected dogs may also have a purulent nasal discharge and a low-grade fever. The more severe syndrome associated with the virus includes pneumonia, lethargy, high fevers (104◦ F – 106◦ F), and increased respiratory rate and effort. Dogs with pneumonia typically have a secondary bacterial infection that is responsive to broad-spectrum antibiotics. There have been fatalities associated with the virus, but the rate is low at 1% – 5% of those infected.
There may be an incubation period of 2 – 5 days before clinical signs are noted. Some animals do not show clinical signs but may still be infected and shed the virus. There is no quick, accurate way to diagnose this virus. The virus is spread by aerosolized respiratory secretions; contaminated toys, bowls and cages; and by individuals not using proper biosecurity when working between healthy and sick dogs. The virus is most likely inactivated by routine disinfectants containing quaternary ammonium compounds or solutions containing 10% bleach. Since the virus is highly contagious and most dogs are susceptible to infection, veterinarians; boarding facilities; shelters; and pet stores should use isolation protocols for any dogs with a cough. People should seek the help of their veterinarian for treatment and diagnostics if their dog becomes ill.
David M. Chico, VMD
Division of Animal Industry
New York State Department of Agriculture and Markets