Yes, dogs can get the flu. Also called canine influenza, this infection is a highly contagious respiratory virus. Dog flu symptoms can be hard to spot, too. It's spread through close contact with sick dogs or contaminated items like shared water bowls or kennels. The symptoms of dog flu resemble a cold: runny nose, cough, and low energy. Most dogs recover in a few weeks, but more severe cases need veterinary care. Fortunately, a vaccine has been developed that can help protect your dog from the dog flu.
Symptoms of Canine Flu
Around 20 percent of dogs with influenza are asymptomatic. However, even if your dog does show symptoms of dog flu, they can easily be confused with other illnesses. Dog flu and kennel cough, in particular, have similar symptoms:
- Nasal discharge
- Discharge from the eyes
- Poor appetite
- Labored breathing
During the initial outbreak in greyhounds, there were numerous deaths from pneumonia and bleeding into the lungs. However, these complications have not occurred on a large scale in the general pet population.
What Is Dog Flu?
The dog flu is a type A influenza virus similar to the viruses that cause flu in humans, birds, swine, and horses. Each type of flu has a different classification based on the proteins on the surface of the virus, abbreviated with an "H" and an "N."
The first strain of dog flu, referred to as H3N8, was identified in racing greyhounds in 2004. This strain originated in horses and mutated to affect dogs. A second subtype of canine influenza, the H3N2 strain, is similar to that in birds. It was first reported in the United States in 2015 and is the primary strain involved in the 2022 and 2023 dog flu outbreak. Both strains are highly contagious.
How is Dog Flu Transmitted?
Canine flu is spread through contact with respiratory secretions through the air, direct contact with another dog, or on fomites (such as shared food and water bowls, toys, brushes, or surfaces). Dogs with flu will show symptoms about five to seven days after being exposed to another sick pet, although they may be contagious to other dogs before that.
Seeing Your Vet
Should you see your vet if you believe your dog has the flu? Most cases of dog flu are mild, but in a few dogs who are sick (less than 10 percent), the flu can be life-threatening.
- Seek veterinary care immediately if your dog is experiencing labored breathing, weakness, severe coughing, or a fever over 105 degrees Fahrenheit.
- All puppies with symptoms of canine flu should see a veterinarian to be checked for pneumonia.
- Make an appointment with your vet if your dog's symptoms persist beyond a few days or get worse.
- If your dog develops a cough, the vet's office may want you to notify them as soon as you arrive so they can take steps to prevent your sick dog from meeting other pets in the lobby.
Diagnosing the Flu
Your veterinarian may decide to test your dog for the flu if they are showing any symptoms. Kennel cough is another common respiratory disease in dogs, and the treatment in a mild case of either flu or kennel cough may be similar, so testing is not always done right away. An exam by your veterinarian will help determine how aggressive the testing and treatment will need to be.
Tests are usually done on a nasal swab or a blood sample. Your vet will send these samples either to a local diagnostic laboratory or Cornell University. Several types of tests are available, but an antibody blood test is the most accurate overall. Sometimes it's necessary to obtain two samples and have them tested two to three weeks apart for accurate results.
In severe cases, a dog may need more advanced diagnostics, such as:
- Chest X-rays
- A complete blood count
- Microscopic analysis (cytology) on a sample from the lungs or throat
- A culture from the lungs or throat
- A blood gas analysis
Treatment for Your Dog
In a mild case of dog flu, your pet will probably need general nursing care and monitoring. Make sure they are drinking water and encourage them to eat. You may need to try a more enticing diet than usual, such as cooked chicken or baby food. If you can, check your dog's temperature. A normal temperature will be between 100 and 102.5 degrees for most dogs. If your dog's temperature is higher, contact your vet right away for guidance.
Medications for Dog Flu
It might be tempting to give them a human medication for fever or to help with the flu symptoms, but this can be dangerous, as many human medications are toxic to dogs. Call your veterinarian for advice before giving any over-the-counter or prescription medications. Some of the medications they may recommend include:
- Antibiotics. There is no cure for canine flu; your dog's immune system needs to fight it off over time. Your veterinarian may prescribe an antibiotic if they suspect your dog is at risk for pneumonia or has kennel cough. The flu virus itself does not respond to antibiotic treatment, but bacterial infections are common secondary complications.
- Cough suppressants. Your vet may suggest using cough suppressants, but only if your pet is coughing so much, they cannot sleep. It is best to let your dog cough up the secretions in the lungs to try to avoid developing pneumonia. The threat of pneumonia increases for puppies, old dogs, dogs with other medical problems, or those on certain medications.
- Tamiflu. Tamiflu has been used experimentally in dogs to treat the virus, but is not routinely recommended because it has to be used early in the infection. The American Veterinary Medical Association also notes Tamiflu has also not been studied for efficacy or safety in dogs.
For those dogs who become seriously ill, hospitalization can be required. Treatment could involve:
- Multiple antibiotics
- Supplemental oxygen
- IV fluids
- Anti-inflammatory medications
Once your pet has recovered from dog flu, follow-up care is not generally needed. In more serious cases, your vet may want to order another set of chest X-rays.
Preventing the Flu in Dogs
There are several ways you can prevent your dog from contracting the flu and help stop the spread.
Fortunately, vaccines are available to protect against both the H3N8 and H3N2 strains of dog flu as well as a bivalent vaccine, which offers protection from both strains. Dogs should receive an initial set of two vaccines given two to four weeks apart, then an annual booster is recommended.
Not all dogs need to be vaccinated against the flu, so you should discuss this with your veterinarian. In some areas, local boarding kennels or daycare facilities will require your dog to have a flu vaccine. Vaccination will decrease your dog's chances of catching the flu and reduce the severity of symptoms if they do get it.
If you learn there is an outbreak of dog flu in your area, you can prevent infection in your dog by minimizing socialization during that time. Avoid dog parks, pet stores, daycare, and boarding if possible.
The American Veterinary Medical Association (AVMA) reports dogs with flu will be contagious to others for seven to 10 days from when they first have symptoms. It is safest to keep your pet away from other dogs for 14 days to help prevent further spread of the flu. In cases with the H3N2 strain, dogs could be contagious for up to 21 days.
Can People Catch Dog Flu?
No, there have been no reported cases of humans with the canine flu. However, the H3N2 strain has been shown to infect cats. As with any influenza virus, mutations are common and could result in a new strain of virus that behaves in a different way.
Help Stop the Spread of Dog Flu
Thankfully, dog flu is not usually serious, and most dogs recover within a few weeks. Keep your canine companion current on their vaccinations to help prevent any unpleasant illness and speak to your veterinarian if you notice any concerning dog flu symptoms.