Canine Influenza - And Why We Don't Vaccinate For It

Happy New Year! Canine Influenza ("CI") has been in the news a lot lately. Maybe this is because it's been a pretty mild year for human influenza, and the press needs something to write about, or maybe because the manufacturer of the new Canine Influenza vaccine has been out beating the bushes. Either way, we've been getting a lot of calls about it.

The CI virus was first identified only a few years ago, and is thought to be a variation of the Equine influenza virus. Initially, it appeared to be extremely virulent, causing severe symptoms or death in infected dogs. It is now considered much less harmful in most dogs (greyhounds seem to be the exception) than originally thought.

Symptoms of CI in dogs are similar to those suffered by people with the flu. Coughing and respiratory congestion are most often seen. Patients may run a low-grade fever, and have lethargy or inappetence. Pneumonia and secondary bacterial infections are rare but serious complications of CI. The disease is remarkably similar to a much more common infection of dogs called "kennel cough."

CI is difficult to definitively diagnose. Titer tests are available, but the disease has usually run its course and the dog is no longer contagious by the time results become available. Most veterinarians suspect CI in dogs who live in areas where the virus is known to be present, who have appropriate symptoms, and who are adequately immunized against kennel cough.

Treatment is mostly symptomatic and supportive. Hydration is very important, and antibiotics may be prescribed to treat or prevent secondary bacterial infections. Sometimes cough suppressants are used to make the dog more comfortable. Severe cases may require hospitalization.

As mentioned earlier, there is a vaccine for CI. Currently, we only recommend the vaccine for dogs who live in locations where CI outbreaks have occurred, and who will be exposed to other dogs (boarding kennels, grooming salons, pet "superstores"). There have not been any known outbreaks in our geographic locale, so we do not currently recommend the vaccine for our patients.