By Tiffany L. Mitchener, DVM
The newspaper headlines have struck fear in every dog owner this summer: “Canine flu has killed two North Carolina dogs…” Charlotte Observer, 6/7/17 • “Dog owners, beware the rise of canine influenza,” The Courier-Journal, 6/29/17 • “As dog flu outbreak widens, experts call for flu shots,” Orlando Sentinel, 6/30/17
What is Canine Flu?
There are two subtypes of flu currently infecting dogs in the United States. The first appeared in January 2004 among racing greyhounds at a racetrack in Florida; H3N8 was originally an equine flu virus, which genetically adapted to infect dogs. It gained the ability to infect dog-to-dog and quickly spread across the United States.
In spring 2015, Chicago became ground zero for another dog flu outbreak. Veterinary officials originally thought it was another H3N8 outbreak. Further testing showed that this outbreak was due to a new canine influenza virus H3N2. This virus was first identified as an avian flu that adapted to infect dogs in South Korea in 2007. The source of the Chicago outbreak has never been identified. Nevertheless, it infected over 1000 dogs in the upper Midwest and within five months had spread to 23 states.
The current flu outbreak, which started in early June 2017, is caused by H3N2. The source of the outbreak appears to be two dog shows, in Florida and Georgia. There have been several confirmed canine deaths. As of this writing, it has continued to spread to eleven states with dozens of newly confirmed cases in Minnesota recently reported.
What dogs can become infected?
All dogs appear to be susceptible regardless of age or breed. Neither canine influenza type has been shown to infect humans. Interestingly, during the Chicago outbreak, it was demonstrated that H3N2 could in rare circumstances infect cats and cause a similar disease.
What are the symptoms of canine flu?
Canine flu has symptoms very similar to the human form of influenza. In most cases, dogs are feverish, lethargic, and sneezing. They have decreased appetite, eye and nose discharge, and a soft, moist, persistent cough. Puppies, senior dogs, and those who are immune-compromised are most at risk of developing more serious infections. In these cases, dogs can develop high fevers and life-threatening pneumonia.
Can my dog get the flu?
In an outbreak, canine influenza can reach nearly 100% infection rates among those animals exposed to the virus. Symptoms usually develop 2-3 days after initial infection. Eighty percent of infected dogs show mild symptoms, and most dogs recover fully in 2-3 weeks. Infected animals continue to shed virus for up to 24 days with the H3N2 virus, making quarantine an important tool used by veterinarians to control an outbreak.
How does the flu virus spread?
The canine influenza virus is highly contagious. It can be spread through direct contact, like coughing, barking, and sneezing. Dogs who are exposed to high dog density situations, like animal shelters, dog shows, dog parks, grooming facilities, and dog day care are considered most at risk.
Canine flu can also spread via indirect contact, meaning that the virus can live on other surfaces, like clothing, toys, floors, food and water bowls, and spread disease for up to 48 hours. Most frighteningly, a dog owner can unknowingly spread the flu to his own dog by petting an infected dog, then petting his own dog. The virus can live on human hands for up to 12 hours. Practicing good hygiene and washing hands with soap and water between petting animals is essential.
What should I do if I think my dog has the flu?
If your dog is showing signs of respiratory disease, a veterinary examination is highly recommended. Most dogs recover with rest and supportive care; however, some dogs will require hospitalization.
Is canine flu here in California?
In March 2017, canine flu H3N2 was documented in dogs that were imported to Los Angeles from Asia and not properly quarantined. The virus has continued to occur sporadically in California.
There is some concern that the virus will continue to spread this summer as more people take their dogs on vacation and unknowingly spread the disease.
Is there a vaccine available?
Vaccines do exist for the canine flu. The H3N8 canine flu vaccine has been available since 2009. In November 2016, a vaccine was made available for H3N2. Two doses are recommended for an appropriate immune response. It is important to discuss your dog’s lifestyle and risk factors with your veterinarian to determine if he should be vaccinated against the canine flu.
How can I prevent my dog from getting the dog flu?
- Avoid close contact with dogs outside the household, especially if dogs have been coughing, sneezing, or have a recent travel history.
- Do not allow your dog to share food and water bowls, toys, blankets, or leashes.
- Practice good hygiene among all human family members; remember to wash your hands with soap and water after touching another dog before petting your own dog.
- Discuss with your veterinarian if vaccination would be recommended for your dog.