Canine Flu – What You Need to Know

Dog Veterinarian
Canine Flu Symptoms Are Similar To Those In Humans

Anyone who has suffered through bouts of flu knows that sometimes it can make you absolutely miserable, while other times if just seems like a bad cold. The same is true for dogs. Although the viruses that cause human and canine flu are different and not transmittable across species, the symptoms are pretty much the same: sneezing, coughing, fever, disinterest in food and general discomfort. You and your veterinarian can team up to help your dog prevent getting the flu or treat its symptoms.


Canine Flu Virus
The Dreaded Influenza (Flu) Virus

Canine virus is caused by the influenza A virus. There are two primary strains: The H3N2 strain appears to have migrated from Asia, whereas the H3N8 strain is an adaptation of a horse flu virus that has become specific to canines. The virus is spread among dogs by coughing, sneezing and barking. It can spread through the air or by contact with contaminated objects, including people. It takes the virus two to four days after infection to begin making your dog miserable. Dogs don’t have any natural immunity to flu, although about 20 percent of infected dogs don’t come down with symptoms.

Dog flu is not thought to be seasonal – it can infect dogs all year long. Canine flu can be accompanied by a secondary bacterial infection, which your vet can diagnose and treat.


Dogs can develop mild or severe cases of flu. In the predominant mild form, you’ll notice symptoms like nasal discharge, coughing (usually moist but sometimes dry), perhaps the occasional sneeze and signs of fatigue and disinterest with food. The symptoms will usually pass after 10 to 14 days.

Severe flu is more dangerous. It can cause dogs to develop fevers above 104 degrees, as well as having difficulty breathing and sometimes coughing up blood, which could be a sign of pneumonia. Other symptoms include runny nose and red/runny eyes. Secondary infections are more common with severe flu, and the worst cases can threaten your dog’s life.

Diagnosis and Treatment

Canine flu can be tested for by your veterinarian by taking swab or blood samples, but it can be difficult to detect. It’s important to have your dog examined when it comes down with symptoms, because a few other types of infection can cause similar symptoms. Your veterinarian might also take chest X-rays to check for pneumonia.

As with human flu, the treatment for dog flu is basically symptom management and patient support. However more aggressive treatment is necessary when a secondary infection is detected, when the dog is pregnant, dehydrated, or has a pre-existing condition such as a collapsed trachea, lung disease, cancer, etc. Note the species with pushed-in faces, such as bulldogs, pugs, Boston terriers and Pekinese, may find it harder to breathe when they catch flu.

Specific treatments may include:

  • Administering anti-microbial drugs when a secondary infection is identified
  • Giving the dog anti-inflammatory, non-steroidal medications to reduce inflammation and fever
  • Provide fluids to fight dehydration
  • Isolate the dog form other dogs for about three weeks so that it doesn’t spread the infection
  • Severe cases in which the dog has pneumonia may require intensive care in an animal hospital or clinic
  • In general, let your dog rest and make sure plenty of water is always available. Check with your veterinarian about any special dietary steps you should take.


Dog Vaccine
A Flu Vaccine Is Now Available For Dogs

The first canine flu vaccine was approved by the USDA in 2009. It contains inactivated flu virus and stimulates the dog’s body to make antivirus. Dogs at greatest risk of getting flu are those that are kept with or visit other dogs, whether in a kennel, at the dog park or at doggy day care. Another group that may benefit from flu vaccine are dogs that have come down with kennel cough, a bacterial infection that resembles flu. Your veterinarian can discuss with you the pros and cons of vaccinating your dog. If you are boarding your dog, ensure the facility cleans and disinfects bowls, cages and other surfaces on a regular basis.  Animal Clinic of Morris Plains maintains strict hygiene standards throughout our boarding areas and we’re AAHA Accredited.