Canine Influenza

Simon helps design some of this site too!

Simon Says (Miniature Schnauzer)
1999-2005
Lost his life due to canine influenza.

Outbreaks of the Canine Influenza virus, which causes an acute respiratory infection, have been identified in dogs in shelters, humane societies, boarding clinics. This illness is highly contagious and is a newly emerging respiratory pathogen in dogs and causes a clinical syndrome that mimics "kennel cough". Canine influenza virus infections are frequently mistaken for infections due to the Bordetella bronchiseptica/parainfluenza virus complex.

Because this is a newly emerging pathogen, all dogs, regardless of breed or age, are susceptible to infection and have no naturally acquired or vaccine-induced immunity. Virtually 100 percent of dogs exposed become infected with this. Nearly 80 percent have clinical signs. There are two general clinical syndromes- the milder syndrome and the more severe pneumonia syndrome. The milder disease syndrome occurs in most dogs.

In the milder disease, the most common sign is a cough that persists for 10-21 days despite therapy with antibiotics and cough suppressants. Most dogs have a soft, moist cough, while others have a dry cough similar to that induced by Bordetalla bronchiseptica/parainfluenza virus infection. Many dogs have a purulent nasal discharge and a low grade fever. The nasal discharge likely represents a secondary bacterial infection that quickly resolves with treatment with a broad-spectrum, bactericidal antibiotic.

Some dogs have a more severe disease with clinical signs of pneumonia, such as a high fever (104-106 degrees F), and increased respiratory rate and effort. Thoracic radiographs may show consolidation of lung lobes. Dogs with pneumonia often have a secondary bacterial infection and have responded best to a combination of broad-spectrum, bactericidal antibiotics and maintenance of hydration with intravenous fluid therapy. There have been fatal cases of pneumonia, however the fatality rate is low (1%-5%).

As for the incubation time of this disease, dogs will show clinical signs two to five days after initial exposure. Infected dogs may shed virus for seven to ten days from the initial day of clinical signs. Nearly 20 percent of the infected dogs will not display clinical signs and become the silent shedders and spreaders of the infection. So if your dog was exposed and shows no symptoms, he can still pass this on to another dog.

There is no rapid test for diagnosis of dogs with an acute influenza virus infection. Current tests rely on detection of antibodies to canine influenza virus, which are detected as early as seven days after the onset of symptoms.

There is no vaccine for canine influenza virus at this time. This virus is spread by aerosolized respiratory secretions, contaminate inanimate objects and even by people moving back and forth between infected and uninfected dogs. This is an enveloped virus that is most likely killed by routine disinfectants, such as 10 percent bleach solution. Because the virus is highly contagious and all dogs are susceptible to infection, veterinarians, boarding facilities, shelters and pet stores should use their isolation protocols for dogs that have "kennel cough."