Canine influenza, or dog flu, is a relatively new virus with two strains: H3N2 and H3N8. The first known case of H3N8 dog flu spread from horses to racing greyhounds in 2004. The first recorded case of the H3N2 strain in dogs originated from birds in 2007. The symptoms of dog flu are similar to the human version of the virus. 

As dog flu is fairly new, our canine counterparts have very little natural immunity. To add to the issue, there's currently no cure for dog flu. Thankfully, dog flu cases are generally mild, and most pups fully recover. 

Concerned your canine companion has dog flu? Scroll down for information on different symptoms, whether humans can get dog flu, tips for preventing the spread of dog flu, and much more!

The Centers for Disease Control (CDC) states that dog flu usually spreads through saliva and mucus droplets from barking, sneezing, coughing, or contact with contaminated objects and surfaces. 

Large gatherings of dogs put your pup at greater risk of contracting canine influenza. Common events and locations where dog flu spreads include:

While dog flu is generally mild, some dogs are at increased risk, including immunocompromised dogs, puppies, older dogs, and pregnant pups. Consult your vet if you're concerned about an outbreak of canine influenza in your area. 

Contact your vet right away if you think your dog has canine flu. Ensure you tell your vet about your dog's symptoms before a clinical visit. As the virus is highly contagious, you or your vet may need to make special arrangements to avoid infecting other cats and dogs. Testing is required to definitively diagnose canine flu, as its symptoms are almost identical to kennel cough. 

Common symptoms of dog flu include:

As there's no specific therapy for dog flu, all treatment is supportive. Luckily, most cases of dog flu are mild, and the disease is lethal in under 5% of cases. Common treatments for canine influenza include:

Most dogs recover fully from dog flu without any adverse side effects. Dogs with weakened immune systems may take longer to recover from canine influenza. Most dogs will recover within two to three weeks. 

No, dogs can't catch the human flu virus strains. While there's some debate surrounding the subject, there's no evidence that dogs can contract any strain of human flu virus.

Dogs may catch the canine flu in the form of H3N2 from cats, however the incidence of dogs and cats passing this illness back and forth is rare. You should still isolate sick pets from healthy ones. The cat flu, which can be a common name for canine parvovirus enteritis, is a highly contagious disease and can be passed between cats and dogs, although it is not a traditional "flu" and has different symptoms. 

No, there's no evidence that dogs can pass either canine influenza strain to humans. So, there's no need to worry about your household becoming ill if your dog is diagnosed with the virus. 

However, there have been rare cases of dogs passing canine flu onto cats. It's worth noting that viruses are constantly mutating, and dog flu's ability to infect humans may change in the future.

Dogs may catch the canine flu in the form of H3N2 from cats; however, the incidence of dogs and cats passing this illness back and forth is rare. Regardless, you should still isolate sick pets from healthy ones.

The cat flu, which is a common name for canine parvovirus enteritis, is a highly contagious illness and can be passed between cats and dogs, although it is not a traditional "flu" and has different symptoms. It should also not be confused with feline parvo which is a different illness.

Yes, there's a single vaccine available that helps protect dogs against both canine flu strains. That said, it's not a core vaccine and is not routinely administered. Dogs as young as six weeks old can receive the vaccine. Two doses are given four to six weeks apart, with a booster jab annually after the second dose. 

You should speak with your vet about whether your dog should have the flu vaccine. As it isn't a core vaccine, certain factors relating to your dog's health and your area's risk level will make a difference in whether your vet recommends it.

Risk factors that can contribute to your vet recommending the flu vaccine for your dog include:

Yes, you can test dogs for canine flu. It's the best way to reliably diagnose the illness, as its symptoms are similar to kennel cough. The most dependable way to diagnose dog flu is with a polymerase chain reaction (PCR) test via a deep nasal swab within four days of the onset of symptoms. 

A PCR test is considered the best diagnostic method, as other methods require two serum tests, one at the beginning of the illness and another two or three weeks later. Contact your vet within the first four days of your dog showing symptoms of canine influenza for the quickest possible diagnosis.

Are you worried about your dog getting canine flu? Here are some tips to prevent your dog from contracting the virus:

As a precaution, you should isolate a dog suspected of having canine influenza for four weeks. Dogs diagnosed with H3N2 canine flu should isolate for 21 days, while dogs with the H3N8 strain should isolate for seven days.