There is new information regarding the canine influenza (CI) outbreak in Chicago and other parts of the Midwest, and it is not encouraging. Information released today indicates that Cornell University, working in conjunction with the University of Wisconsin, have found that the causative agent is not the H3N8 strain as previously thought; rather, the virus responsible for this outbreak is the H3N2 strain. The Sun Prairie Pet Clinic does not know the specific strain of the virus found in the Dane County case. The H3N2 virus has been identified previously in Asia, but never before in North America.

The H3N2 strain has been in wide distribution in Asia (southern China and South Korea) since it was found in 2006. This virus causes a similar respiratory disease in dogs as the H3N8 version, though many clinicians feel that the symptoms are more severe with the Asia strain. The overall mortality rate is similar at about 5%. Humans are not susceptible to this virus, but it has been shown to infect and cause respiratory disease in cats. There is no vaccine available for the H3N2 strain of the canine influenza virus.

With this new information, several new questions arise. How is this virus transmitted? How can I protect my dog? Is there a vaccine available? We know the answer to some, but not all, of these questions.

As with the H3N8 strain, the best way to slow the spread of this disease is avoidance of areas where dogs congregate, good hygiene, and good sanitation. This strain transmits in the same manner as H3N8, with dog-to-dog contact the primary route. The virus remains viable (alive) on solid surfaces for 48 hours and clothing for 24 hours. The virus is killed with a wide variety of disinfectants, and routine hand washing with soap and water is effective in removing the virus from hands.

The canine influenza vaccine currently available provides good protection from the H3N8 strain of canine influenza. Protection from the H3N2 strain has not been tested and cannot be assumed. Cross-protection may by present; it simply has not been tested to date.

After taking all these factors into consideration, the Sun Prairie Pet Clinic recommends that dog owners continue to take the same precautions previously put forward – avoid areas where dos congregate if possible, avoid kenneling dogs if possible, and monitor the number of cases locally to judge risk of these activities.

The currently available vaccine is safe and effective at preventing disease from H3N8 Canine Influenza virus but has not been tested against the H3N2 strain. It is possible that the current vaccine can provide some benefit to dogs against H3N2. Because this vaccine is safe, effective against a serious canine respiratory disease, cost effective, and might help with the Asia strain of canine influenza, continued use of this vaccine is advocated.

As more information is made available, we will update this site.

Click here for the updated information from Cornell University