The American Veterinary Medical Association (AVMA) is reporting that the ongoing canine influenza outbreak in Chicago and parts of the Midwest has been traced to a different strain of the virus than originally believed. This marks the first identification of the H3N2 subtype outside of Asia, according to US researchers.

20 June 2017

There are two distinct strains of flu in dogs: 

H3N8

-The first cases of H3N8 were seen in 2004, and since that time some dogs may have been exposed to and have built up some immunity to H3N8. 

H3N2

-The first cases of H3N2 were reported in 2015. Most dogs have have had no exposure to it and hence no immunity to this strain of influenza virus. Most of the cases in recent news have been of the H3N2 strain of influenza, although a few dogs also tested positive for the H3N8 strain. At a recent dog show in Florida, over 230 dogs were stricken with flu with almost 100% of the dogs at the show reporting illness within 7 days of the end of the show. Four deaths were reported, and an average of 10 days of hospitalization was required in those dogs requiring hospitalization. Overall, recent statistics show over 600 dogs (in the southeastern US) affected by the H3N2 virus in a short period of time.

Symptoms

Symptoms of the H3N2 virus include coughing, sneezing, nasal discharge, lethargy, weight loss, dehydration, vomiting, and lack of appetite. Any dog that is around other dogs is at risk, or dogs that go to a boarding facility, groomer, day care, or dog park. Puppies and older dogs or dogs with weakened immune systems also have a greater risk for potentially life-threatening complications such as pneumonia.

Virus Spread

The incubation period for the virus is 2-7 days, with infected individuals passing the virus on the for several days before they present symptoms themselves. Symptoms may last anywhere from 7 days up to 3 weeks. Dogs can continue to pass the virus on for up to 4 weeks after symptoms start. It is important to isolate sick pets for at least 4 weeks from the first onset of symptoms.

Most people are not even aware that canine influenza exists, so allow their dogs to sniff and lick each other in parks etc, thus spreading it further.

Vaccination

To date, the H3N2 virus has not yet become common as far north as Canada. However, you should check with your veterinarian on the advisability of vaccinating your pet for canine influenza should the disease spread to our region.


Precautions for Dog Owners

- Keep your dog away from other dogs if it is sick. Influenza viruses are only shed for a short period of time, so keeping sick dogs away from other dogs for 7-14 days can be useful.

- Keep your dog away from other dogs if it has been exposed to dogs that might have been infected. It doesn’t matter if your dog is healthy. Peak flu shedding can occur very early in disease, and many viruses can be shed in the 24 hours before the dog starts to show signs of illness. So, keeping exposed animals away from others for 7-14 days after exposure is a good idea.

- Don’t travel out of an endemic region with your dog. Don’t take your dog on a trip if you live in an area where H3N2 is active. Your dog could take the virus to a new region if it was infected before leaving.

- Don’t import dogs from shelters, puppy mills or other high risk facilities from areas where H3N2 is active.

- Decrease dog-dog contact if the virus is active in your area. Staying away from places where lots of dogs congregate can reduce the risk of exposure.

- Don’t rush it to your vet if you think your dog might have canine flu. It might need to go to the vet, but that depends on severity of disease. Regardless, the best approach is to call first and mention the potential for influenza so the vet clinic can take precautions.

For further information see: https://www.canadianveterinarians.net/news-events/news/canine-influenza-info-for-vets-and-dog-owners