Zoetis, Merck receive conditional licensing for canine flu vaccines

Zoetis and Merck Animal Health have both received conditional licensure from the U.S. Department of Agriculture (USDA) to market vaccines for the prevention of the H3N2 strain of canine influenza virus, according to company releases.

Earlier this year veterinarians in more than 20 states found themselves fighting an outbreak of canine influenza, specifically the H3N2 strain, for which there was not a vaccine. The only vaccines on the market were formulated to protect against H3N8. The outbreak started in Chicago, where an estimated 2,000 dogs became ill.

Ann Cohen, DVM, of Chicago Veterinary Emergency & Specialty Center, which treated many of these sick dogs, says that since June they've seen small outbreaks, but nothing like the initial outbreak. “The dogs are not as ill and there are far fewer of them,” she says. “We continue to recommend that veterinarians perform respiratory panels on dogs where there is a suspicion of canine infectious respiratory disease to monitor disease progression and offer direct treatment.”

Veterinary health experts hope the addition of two new vaccines that protect against this particular strain of canine influenza will curb the spread of the virus and prevent another outbreak on the same scale as the one from early this year.

The Zoetis vaccine is formulated with killed virus and is to be administered in two doses, three weeks apart, to healthy dogs 8 weeks old or older, with annual revaccination recommended, the Zoetis release states.

The Merck vaccine is recommended for healthy dogs 6 weeks or older and is also formulated with killed vaccine, the Merck release says.