Diseases, Shelter and Rescue Resources

H3N8 Canine Influenza

Canine influenza (CI) is a contagious respiratory disease in dogs, and it can spread very quickly among dogs. Because it’s a relatively new disease, most dogs have no immunity to the virus. However, with proper care and prevention, your dogs can escape with few lingering effects.

Canine Influenza Origin

Canine influenza, also known as dog flu, is thought to have mutated from equine influenza. It was first found in racing greyhounds in 2004. Since then, it’s been detected in 30 states. Because it’s a respiratory disease, it spreads quickly through direct contact and airborne pathogens, especially in locations like kennels, clinics, dog parks, groomers and more. An estimated 80 percent of dogs who come in contact with the virus will develop the disease.

Canine Influenza Symptoms

The most common symptom of canine influenza is a persistent cough that lasts up to three weeks. Secondary infections may also cause sneezing, nasal discharge and a low-grade fever. Severe cases include an increased respiratory rate and a high-grade fever, often with pneumonia. Since the symptoms are similar to other diseases such as kennel cough, canine influenza is difficult to diagnose without an oral swab to look for the specific pathogen.

How to Treat Dog Flu

There is no antiviral treatment for canine influenza. Supportive care, good nutrition and vitamins are necessary to boost the dog’s immune system so he can fight off the infection. Antibiotics can also be used to treat the secondary infections. A more severe form of the virus might require fluids to prevent dehydration. Breeder’s Edge Puppy Lyte or Shelter’s Choice Electrolytes are helpful dog electrolytes to have on hand to help maintain hydration and replenish electrolytes. Most dogs recover from the disease within a few weeks, but secondary pneumonia can be life-threatening, with a five to eight percent fatality rate.

Since the canine influenza virus is easily killed by disinfectants, thorough cleaning habits can control the virus from spreading. Follow isolation protocols for any dogs with the virus, keeping them separate from healthy dogs. Always wash your hands and the supplies you use after caring for an infected dog.

Prevention: H3N8 Vaccine for Dogs

There is a H3N8 vaccine for dogs available for canine influenza, but it only reduces the severity of the disease; it does not prevent it. These vaccines are made with a killed version of the virus, so there’s no chance of infection. Tests have shown vaccines are well-tolerated with minimal side effects. Since many dogs have routine contact with other dogs, most dogs are candidates for the vaccine. Annual re-vaccination with a single dose is recommended.

As with any disease, sanitary living conditions and quality health care are necessary to prevent serious diseases. Avoid taking your pet anywhere they might have contact with unknown dogs. If your dog could potentially come in contact with canine influenza, consider vaccinating against the disease. Although influenza can be a serious disease, it can also be handled effectively to keep your dogs healthy and strong.

Vaccinating your dogs with lifestyle risks of exposure to other dogs should also include the 3-way intranasal Bordetella/ parainfluenza/ adenovirus vaccine.

If you have more questions on canine influenza or the H3N8 vaccine for dogs, call us at 800.786.4751.

Article originally written by Donald Bramlage, DVM, Revival’s Former Director of Veterinary Services. This article has been updated/reviewed by Dr. Greer.

Written by: Marty Greer, DVM

Director of Veterinary Services

Marty Greer, Doctor of Veterinary Medicine, has 40+ years’ experience in veterinary medicine, with special interests in canine reproduction and pediatrics. She received her Doctor of Veterinary Medicine from Iowa State University in 1981. She’s served as Revival’s Director of Veterinary Services since 2019. In 2023, Dr. Greer was named the Westminster Kennel Club Veterinarian of the Year.

If you need help, call us at 800.786.4751.