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Instead, this contagious upper respiratory illness is spread among other dogs, especially in crowded conditions such as boarding facilities, shelters, or doggy daycares where its common to see dogs exposed.
The good news is that supportive care treatments are generally effective, the mortality rate is low with canine flu, and there is a vaccine available. Here’s what dog owners should know about dog flu and respiratory disease.
What Is Canine Influenza (Dog Flu)?
Canine influenza virus (CIV) is a highly contagious upper respiratory virus that can affect dogs (and cats). The two strains that have been identified are H3N8 (identified in 2004 in Florida)Â Â and H3N2 (identified in 2015 in Chicago).
The disease is spread between dogs by direct contact, respiratory secretions (sneezing, coughing, nasal discharge), or contaminated objects (such as food bowls, kennels, or on the skin or clothing of people who have interacted with infected dogs).
The virus can survive for 12 hours on the skin and for up to 48 hours on objects.
Unlike human flu, there is no season for the canine influenza virus, and it can occur year-round. Any age or breed of dog can become infected, although very young puppies, seniors, dogs with other underlying medical conditions, and brachycephalic breeds (with flat faces) are at higher risk for more severe disease.
Symptoms of Dog Flu
Dog flu symptoms are similar to other upper respiratory infections, such as kennel cough, and may include:
- Persistent cough for 10-30 days
- Thick nasal discharge
- Fever
- Lethargy
- Eye discharge
- Decreased appetite
- Can develop pneumonia in severe cases
- In mild cases, an infected dog may be asymptomatic but still contagious
Less than 10% of dogs die of canine influenza and most dogs recover. However, if you notice these clinical signs or flu like symptoms, it is important to contact your vet.
Due to the contagious nature of these upper respiratory illness, they may ask you to wait in the car or use a separate entrance to help with disease control and avoid spreading disease to other dogs.
How is Dog Flu Diagnosed?
In the first few days of infection, influenza can be diagnosed on PCR testing from a swab taken from the nose or throat.
However, as the disease progresses, this method of testing will become less accurate. In this case, your vet may perform bloodwork and compare the antibody levels in samples taken two to three weeks apart. Both PCR and serology (blood) testing take time to run.
Depending on how sick your dog is, your vet may recommend additional tests, including bloodwork and x-rays, to rule out other diseases such as pneumonia.
Dog Flu Treatment
There are no specific treatments for canine influenza, therefore recommendations from your vet will depend on the severity of the disease and the symptoms that your dog is experiencing.
Sick dogs should be well cared for with supportive care and isolated from other animals for approximately three weeks.
They will be most contagious for the first two to four days of illness.
Additional treatments may include:
- Prescribe antibiotics for secondary bacterial infections
- Fluids to maintain hydration
- Hospitalization in severe cases
Steps should also be taken to disinfect your home, if you have other animals present.
How Can Dog Flu be Prevented?
There is a vaccine available, and you should discuss with your vet whether it may be recommended for your dog.
In general, vaccination is recommended for dogs with high risk of exposure (frequent contact with other dogs or living in an area with an influenza outbreak) or with other risk factors that may predispose them to more severe disease if they were to become infected.
While the vaccine may not completely prevent disease, it aims to decrease the severity and length of illness.
When a dog first receives their flu vaccine, they will require a booster shot two to four weeks later. After that, the vaccine is due yearly.
Luckily people cannot get the canine flu, and human influenza cannot infect dogs. However, as strains of the influenza virus are constantly changing and mutating, it is possible that this may change at some point in the future, although the risk is low.Â
Your dog’s risk of exposure will depend on your location and lifestyle. Dogs who are mostly at home will have a lower risk of the flu than other dogs who attend doggy daycare, dog parks, boarding, or dog shows. Almost all dogs who are exposed to the flu will become infected, with 80% developing clinical signs.Â
Symptoms may last from 10 to 30 days, however, most dogs recover in two to three weeks.Â
Liza is a veterinarian who graduated from MSU CVM in 2013 and spent five years working in small animal practice. She loved working with dogs and cats and educating owners on all aspects of veterinary medicine, especially animal behavior and dermatology. She has since transitioned to remote work to be able to spend more time at home with her husband, two young kids, and two cats. She is thrilled to be able to combine her passions for veterinary medicine and writing. She is licensed as a veterinarian in Washington State.