Dog flu sweeps the U.S. with two more confirmed cases in Washington state

Jim Evermann

When a new strain of flu virus sickened 1,000 dogs and killed 5 in Chicago back in April, animal health experts wondered just how bad subsequent outbreaks would be. Now, more cases are cropping up across the country, setting off red flags from vets and pet owners.

The American Veterinary Medical Association (AVMA) released information showing that a highly contagious strain of dog flu, H3N2, is sweeping through the U.S. Over the summer, the virus was confirmed in dogs in Atlanta and Charleston, SC. Now there are two more confirmed cases of H3N2 in dogs in Washington state that had already tested positive for influenza A. Both dogs had mild symptoms and have since recovered, the Washington Animal Disease Diagnostic Laboratory (WADDL) said in a statement.

More than 25 states are dealing with H3N2 canine influenza cases, and some experts think that the virus has traveled to more than 40 states. Another case recently appeared in Austin, TX, the Tech Times reports, pointing to a growing problem.

Younger and older dogs could be hit the hardest, as well as those that have other contagious diseases, Jim Evermann, professor of infectious diseases at WADDL, said in a statement. "For that reason, we are advising all dog owners to check and make sure their animals are up to date on their core vaccines" including canine distemper and canine parvovirus, Evermann said.

Fewer than 10% of dogs died from canine pneumonia stemming from the virus, and most recover in two to three weeks, according to the AVMA. But H3N2 can transmitted quickly between animals and is more difficult to stop. "It starts and it will move through an area like wildfire. It gets into the kennels, rescues and shelters," Texas-based veterinarian Dr. Luann Ervin told the Tech Times. H3N2 can also spread to cats and there are no vaccines to protect those animals.

While some vets debate the necessity of a flu vaccine for dogs, others recommend the measure, especially for animals in close proximity. Seeing an opportunity, Merck ($MRK) and Zoetis ($ZTS) have stepped up to the plate with new canine flu vaccines.

The companies in November got a green light from the USDA to market canine influenza H3N2 vaccines, which are administered in two doses a few weeks apart. The jabs do not protect against a previously known strain of dog flu, H3N8, though, so dog owners who want more protection for their pets will need to get separate vaccines. Vets will set the price of the new vaccines but Zoetis' product will likely cost $25 to $35 per injection, a company spokeswoman said last year.

- here's the WADDL statement
- read the Tech Times story
- get more from the AVMA

Read more on