PULLMAN, Wash.—The Washington Animal Disease Diagnostic Laboratory (WADDL) has had two dogs test positive for influenza A but specific typing has not been conducted.

The laboratory cautions that the tests conducted on samples sent from the west side of the state are a generalized test for influenza A in dogs and are not designed to show if they are the strain of most concern, H3N2.

There are two types of canine influenza A viruses, H3N8 and H3N2 and both cause a contagious respiratory disease in dogs.  No human infection with canine influenza viruses has ever been seen.  Nonetheless, the CDC and its partners are monitoring the canine influenza viruses as well as other animal influenza viruses closely.

“Additional samples from the influenza positive dogs are being requested for additional influenza typing to determine if the infection is due to H3N2,” said Kevin Snekvik, a veterinary pathologist and WADDL Director of Operations.

The influenza A H3N8 virus now specific to dogs originated in horses and evolved over some 40 years and jumped species to dogs.  Continued mutation led the virus to be able to be transmitted from dog to dog.  By 2005, it had mutated to a form specific to dogs.

The influenza A H3N2 virus originated in birds and adding to the confusion, it is different than the H3N2 seasonal flu that affects people.  The canine form was found in dogs in 2007 in South Korea.  It has also been reported in China and Thailand and was first detected in the U.S. in April 2015.

The signs of canine influenza can vary widely.  Some dogs will show no signs at all.  Others will be very ill and a small number may die. Dogs usually display a cough, runny nose, and fever. If pneumonia occurs and is untreated, it can result in death.

Most dogs are susceptible to canine influenza.  The illness tends to spread among dogs housed in kennels, shelters, or originates in other group settings.  The disease spreads to other dogs by direct contact with aerosolized respiratory secretions from the coughing and sneezing of infected dogs.  The droplets can also contaminate surfaces and spread the disease to uninfected dogs coming into contact with contaminated objects.

Care for dogs infected with either of the canine influenza viruses centers around supportive care and a watchful approach to worsening symptoms or secondary bacterial infections.  As with most diseases, the very young, the very old, and those dogs with compromised immune systems will be hit hardest and require the most attention.

There is an approved vaccine for the H3N8 virus and it is believed to provide some unmeasured level of cross-protection for H3N2 infections.  A new vaccine for the H3N2 type was just given conditional approval this month.  So far it the level of protection it provides has not been determined.

“In all cases, your veterinarian is the best source of information for canine influenza and your dogs,” explained Dr. Snekvik  “They can advise you on vaccination and prevention of the disease as well as provide medical care if you have a sick animal.”

WSU veterinarians say dogs also get colds, just like people.

Dogs can suffer with a common cold virus and importantly, that is not the same as a bacterial infection known as “kennel cough.”

They may have a cough but it will likely be dry range from mild to severe.  Dogs with influenza A can more often have a severe cough.

The cold virus does not cause a fever in most dogs but the influenza A viruses can cause a fever of 104 to 105.

Colds usually lack sneezing and discharge from the eyes, whereas the influenza A viruses may cause sneezing and discharge from the eyes is more common.

Influenza A signs can persist for up to a month while colds rarely last beyond a week.

Finally, cold viruses act slowly and may take up to 10 days to manifest.  The canine influenza viruses affect dogs within two to four days.


Charlie Powell, Public Information Officer, call or text 509-595-2017 or cpowell@vetmed.wsu.edu