Canine Influenza Virus

Canine influenza virus, commonly known as dog flu, is a highly contagious respiratory infection affecting dogs across the United States. Initially identified in racing greyhounds in 2004, this virus has since spread to a wide range of canine populations. There are two primary strains, H3N8 and H3N2, each stemming from mutations of virus strains originally affecting horses and birds, respectively. Symptoms can range from mild to severe and typically include coughing, nasal discharge, fever, lethargy, and in some cases, pneumonia. Vaccines are available and are recommended for dogs frequently exposed to crowded conditions, such as kennels or dog shows. Preventative measures also include isolating infected animals and maintaining sanitary conditions in facilities that house dogs. As outbreaks can occur rapidly and with little warning, understanding and vigilance are key to managing the spread of the canine influenza virus effectively.

Dr. Sargent and Dr. Giffen from Peterborough West Animal Hospital would like to share some facts on Canine Influenza with all of our dog lovers out there.

Canine Influenza is similar to human influenza. It is a virus. The one that is of concern in Canada is H3N2 canine influenza virus (CIV). Thankfully, the doctors at Peterborough West Animal Hospital tell us that we don’t have to worry about our dogs catching the same colds we do. “Dogs do not usually get human influenza and humans do not usually get canine influenza.” Canine Influenza is a respiratory infection that is spread through coughs, sneezes, nose-to-nose contact with other dogs. Symptoms of canine influenza include coughing, sneezing, fever, runny nose, eye discharge, and heavy breathing.”

Dr. Sargent and Dr. Giffen want our clients to know originally there were a few cases of canine influenza reported in Essex County and Simcoe-Muskoka region in Ontario, but additional cases of dogs infected with H3N2 canine influenza virus have now been reported in Northumberland County, Ontario. This is getting close to home for us! For more information specific to our area, please read our article on Canine Respiratory Disease: What Peterborough, ON Dog Owners Need to Know.

Dogs are more likely to pick up respiratory infections in daycares, dog training classes, grooming facilities, dog parks, and kennels. You have to weigh the risks of protecting your dog rather than giving your dog social exercise and helping them run off that extra energy.

If your dog is sick (depressed, cough, runny eyes, runny nose, and decreased appetite), keep your dog home and away from other dogs (for 4 weeks) and call Peterborough West Animal Hospital and request an appointment. Make sure to tell us the symptoms so we can take proper infection control measures to prevent potential exposure to other animals at the clinic. If you see a dog that appears ill, keep your dog away from it.

If you are concerned about your dog contracting the canine flu there is an influenza vaccine available. This vaccine is the best protection that we have for the H3N2 canine influenza virus (CIV). We now have the vaccine at Peterborough West Animal Hospital. To schedule a vaccination or learn more about protecting your pet, visit our Veterinary Wellness & Pet Vaccinations page.

Canine Influenza Virus in 2025: Transmission, Prevention, and Vaccination

Can cats be infected with canine influenza?

Canine influenza, specifically the H3N2 virus, primarily affects dogs and does not typically infect cats. Cats are susceptible to different types of respiratory infections, most commonly the feline herpesvirus and calicivirus, but not the canine influenza virus. While there have been isolated incidents where cats have contracted canine influenza, these cases are exceptionally rare and not considered a standard risk. Therefore, cat owners should focus on vaccinations and preventive measures relevant to feline-specific respiratory ailments.

How long should infected dogs be isolated?

Infected dogs should be isolated for four weeks to prevent the spread of canine influenza. This virus, known as H3N2, is highly contagious among dogs and can lead to symptoms such as coughing, runny nose, and fever. During this period, it’s critical to avoid contact with other dogs and public places where dogs congregate, such as parks and kennels. If your dog shows signs of illness, contact your veterinarian immediately for guidance and to discuss potential vaccination.

Are there any risks of canine influenza to humans?

Canine influenza, primarily caused by the H3N2 virus, poses no significant risk to humans. This respiratory virus, while similar to the human flu, is species-specific. Transmission between dogs and humans is highly unlikely. Symptoms in dogs include coughing, sneezing, fever, and nasal discharge, and although the disease can spread among dogs, it does not typically cross over to human populations. For dog owners concerned about their pet’s health, vaccines against H3N2 are available and provide the best protection for dogs against this strain of canine influenza.

How long can the virus survive in the environment?

The H3N2 canine influenza virus, which affects dogs, does not survive long in the environment. Under typical household conditions, this virus remains viable on surfaces for about 48 hours, on clothing for 24 hours, and on hands for up to 12 hours. However, its viability can be significantly reduced through the use of common disinfectants, thorough cleaning, and proper hygiene practices. Ensuring these measures are followed can help prevent the spread of the virus among dogs.

How effective are canine influenza vaccines?

Canine influenza vaccines, particularly against the H3N2 strain, are highly effective in preventing the virus in dogs. These vaccines not only reduce the likelihood of dogs contracting the disease but also mitigate the severity of symptoms and the duration of the illness if they do get infected. Vaccination is especially recommended for dogs that frequently interact with others in communal settings like daycares, parks, and kennels. Regular vaccination helps in maintaining the overall health of the pet population and reducing the spread of the virus.

If you have any questions about the vaccine or whether your dog should be vaccinated, please call us your local animal hospital in Cavan Monaghan, ON!.