Yes, there really is such a thing as the dog flu! It is a contagious respiratory disease in dogs that is caused by a Type A influenza virus. There are two known strains of canine influenza (dog flu), the H3N8 virus and the H3N2 virus. In 2004, 24 greyhounds at a Florida race track became ill with what was first believed to be “kennel cough”. As their symptoms progressed and eight of the original 24 dogs died, doctors became concerned that they were dealing with not just kennel cough, but a possible unknown disease. By 2005, doctors were able to determine that the respiratory illness the dogs had been infected with was actually equine influenza A(H3N8) virus. As it so happens, the dog track where the greyhounds originally fell ill also hosted horse racing. Medical professionals believed that the virus had jumped species from horses to dogs and adapted into a canine-specific viral strain. While it was not uncommon for a flu strain to jump to new host species, dogs had always in the past been considered resistant to the flu.
By 2018, the H3N8 influenza strain could be found in almost every state across the United States. Influenza strain H3N2 originated in birds in Asia and then spread to dogs. It has also been reported recently to have spread to cats. It was first detected in South Korea in 2007, but by 2015 could also be found in Canada and the United States. This strain as well can now be found across much of the United States.
Can People Catch the Dog Flu?
No, there is currently no evidence that humans can be infected by either strain of the canine influenza virus. There has never been a single reported case of someone being infected by canine influenza. The Center for Disease Control and Prevention consider canine influenza to be a “low threat to humans.” That being said, influenza viruses are constantly changing and adapting, and it is always possible that a virus can mutate to the point where they can infect a new host type. And while the chance of that happening is very low, the impact could be devastating. If a new influenza A virus were able to jump to humans, people would have little to no immunity against the virus and a pandemic could result. For that reason, the World Health Organization has implemented a global surveillance system to detect human infections by animal-origin influenza A viruses.
What Are the Symptoms of Canine Influenza (Dog Flu)?
Symptoms for canine influenza can appear similar to kennel cough and bordatella and can include a cough, fever, runny nose, reduced appetite, lethargy, and sneezing. Some dogs can appear completely asymptomatic (ie, have no visible sign of infection), while others can have severe symptoms and can even progress to pneumonia or death. Approximately 80% of dogs that are exposed to canine flu will only result in a mild infection. All dogs infected with canine flu are contagious, regardless of the severity of their symptoms. Most dogs will recover from the flu within two to three weeks, however, in severe cases, the flu may progress to pneumonia. Pneumonia symptoms include difficulty breathing, high fever, and thick, pus-like nasal discharge. Because the clinical symptoms for canine flu can mirror other canine respiratory diseases, diagnosing canine flu can be challenging. There are currently no in-office tests available to veterinarians. Tests must be sent out to laboratories.
How is Canine Flu Treated?
Treatment for dog flu involves primarily a palliative treatment plan. Dogs are kept hydrated and comfortable during their recovery period. Dogs are normally not medicated unless a secondary bacterial infection is suspected, which will be treated with antibiotics. The disease is highly contagious, so the animals should be isolated from other dogs and pets.
How is Canine Flu Spread?
Almost all dogs are susceptible to canine flu. Due to their communal nature, the flu virus tends to spread quickly among dogs housed in kennels, shelters, dog parks, and dog daycares. The dog flu is thought to spread primarily through respiratory droplets produced during coughing and sneezing from infected dogs, or through contact with a contaminated surface. Clothes, surfaces, hands, equipment, and toys should be cleaned and disinfected after exposure to a dog with signs of the flu.
Is There a Vaccine for Canine Flu?
Yes, there are vaccines to protect against both the H3N8 and H3N2 strains of canine flu. Some vaccines even protect against both strains at once. The vaccine is regarded as being generally safe and effected, but it may not be for every dog. For that reason, you should consider your dog’s lifestyle before determining if the vaccine is right for your animal. If your dog never or rarely comes into contact with other dogs, this vaccine may not be right for you.
How Can I Get More Information
Your veterinarian will always be the best source of information on the medical care of your dog. Consult your veterinarian to determine if an appointment is needed. If you would like to get more information on the canine flu, please check out the following links and articles that were referenced for this article:
- Influenza A Virus (H3N8) in Dogs with Respiratory Disease, Florida (Emerging Infectious Diseases)
- AVMA websiteExternal
- April 2015 Chicago H3N2 canine influenza outbreak
- Dogster Newsletter
- Media Briefing on Canine Influenza. September 25, 2005.
- Update on Canine Influenza (Dog Flu) Outbreak Reported in Chicago Area. April 13, 2015.
- Influenza A Virus (H3N8) in Dogs with Respiratory Disease, Florida. Volume 14, Number 6 – June 2008.
- Canine influenzaExternal.