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By Dr. Kris Hallden
Published: November 19, 2009

Canine Influenza Virus (CIV) was first identified in 2004 in Florida racing greyhounds. The virus causes coughing and sneezing like other causes of Canine Infectious Respiratory Disease ("Kennel Cough"). This dog virus has NOT been found to infect humans or other animals.

CIV is established in 5 states: Colorado, Florida, New Jersey, New York, and Pennsylvania. At least 30 states have identified cases of CIV, including Oregon (two cases in 2005). Surveillance studies and screening programs monitoring the virus have not identified any current outbreaks. The virus is expected to become more widespread.

CIV is highly contagious to dogs, infecting 100% of those exposed (unless they have immunity from a prior CIV infection). ALL breeds and ages are susceptible. Incubation time is short, only 2-4 days, during which much virus is shed. Dogs may appear healthy even though they are shedding virus and infecting others. In infected dogs, 80% show clinical signs, 20% have subclinical infection. ALL infected dogs are contagious to other dogs.

Up to 10% of CIV infected dogs may develop secondary bacterial pneumonia, typically associated with a fever >104 degrees, and requiring aggressive supportive care. Pneumonia can lead to death.

Vaccine is now available. Dogs travelling to higher risk geographic areas should consider vaccination. Dogs with chronic disease, the old or infirm should consider vaccination to reduce pneumonia risks. Vaccination may be considered for dogs frequenting locations where multiple dogs interact, socialize or share "airspace" including parks, boarding, daycare and grooming facilities.

Vaccination has been shown to reduce the risk of pneumonia and lessen lung damage. Vaccination reduces the total volume and duration of virus shed by an infected dog.

Vaccination requires two doses administered 2-4 weeks apart and then an annual booster. Strong antibody response is achieved by 2 weeks after the second dose. This is a killed virus product. Safety studies found no reported vaccine-associated adverse reactions. This product has been conditionally approved ("fast track").

Reasonable Expectations Regarding the Vaccine and Its Benefits

The vaccine will NOT prevent infection or clinical signs in dogs, but it helps significantly lessen the severity of signs and duration of illness; thereby decreasing risk of pneumonia. It also does not prevent shedding of the virus (just lessens total volume shed. These are very positive actions. Please refer to the following link for more information about Canine Influenza Virus, visit