Canine Influenza Vaccine: All About the Dog Flu Shot

Canine influenza, or dog flu, is a highly contagious respiratory disease. Caused by the canine influenza virus, canine influenza was first reported in dogs in the United States in 2004 and has since been reported in 46 states. Most of these reports have been isolated disease outbreaks, indicating that canine influenza hasn’t gained a strong foothold in the general dog population.

Many dogs have not been exposed to the canine influenza virus, meaning they don’t yet have immunity to the disease. According to the American Veterinary Medical Association, about 80 percent of dogs exposed to the virus will get sick with symptoms like a soft, moist cough, nasal discharge, and lethargy.

Canine influenza is rarely fatal, but it can make dogs feel crummy. Because this disease is highly contagious, protecting dogs from exposure to the canine influenza virus is important.

The canine influenza vaccine is the best way to protect dogs from this disease. The more dogs that get vaccinated, the less the virus will be able to circulate throughout the dog population and cause disease.

What Is the Canine Influenza Vaccine?

There are currently two canine influenza vaccines, and both are FDA approved. They are available in veterinary practices nationwide, with no need to see a veterinary specialist to get the vaccine.

This vaccine is considered a non-core vaccine, meaning that not every dog needs to receive it. The 2022 American Animal Hospital Association (AAHA) Guidelines state that non-core vaccines are “recommended for some dogs based on lifestyle, geographic location, and risk of exposure.”

Because the canine influenza vaccine is not a core vaccine, there are currently no legal requirements on the state or municipal level for dog flu vaccination. However, certain animal facilities, such as doggie daycares and boarding facilities, may require dog flu vaccination to prevent the spread of the disease in the facility.

How Does the Flu Shot for Dogs Work?

The canine influenza vaccine is a bivalent vaccine, meaning that it protects against the two strains of the canine influenza virus: H3N2 and H3N8.

The vaccine is made up of inactivated (killed) canine influenza virus. The killed virus will stimulate the immune system without causing disease. However, compared with other vaccine formulations, killed virus vaccines may have a shorter duration of immunity and may cause more negative side effects.

The canine influenza vaccine also contains adjuvants that help boost the immune response.

Note that the vaccine does not provide 100 percent protection against the dog flu. However, it does help reduce the duration and severity of illness in dogs that get the disease.

Canine Influenza Vaccination Schedule for Dogs

According to the AAHA Vaccination Guidelines, the canine influenza vaccination schedule is two doses 2 to 4 weeks apart, followed by an annual booster. It can be given to any dog who is over 8 weeks old. 

Possible Side Effects of the Dog Flu Shot

As with all dog vaccines, the canine influenza vaccine comes with potential side effects. Most dogs tolerate the vaccine very well and have either mild or no side effects, while some dogs may have severe adverse reactions that require medical attention.

Here are the more common and mild side effects of the canine influenza vaccine:

• Pain and swelling at the injection site
• Lethargy
• Reduced appetite

Serious side effects are listed below:

• Hives
• Collapse
• Persistent vomiting or diarrhea
• Swelling of the face, neck, eyes, or muzzle

Seek immediate veterinary care if your dog develops severe side effects after vaccination.

The canine influenza vaccine does not react with medications or other vaccinations.

Manufacturers of the Canine Influenza Vaccine for Dogs

Merck and Zoetis each manufacture the canine influenza vaccine.

Merck’s canine influenza vaccine is the Nobivac Canine Flu Bivalent. It was the first vaccine to demonstrate effectiveness against both strains of the virus. It received FDA approval in 2017 and can be given to dogs 7 weeks and older.

The canine influenza vaccine from Zoetis is called Vanguard CIV H3N2/H3N8. It also received FDA approval in 2017 and can be given to dogs 8 weeks and older.

Zoetis does have monovalent canine influenza vaccines that protect against one or the other strain of canine influenza virus. However, on their website, the company “strongly recommends that these vaccines be used only if a dog is lacking vaccination against one of the two strains, and then continue with the use of Vanguard CIV H3N2/H3N8.”

Costs of the Canine Influenza Vaccine

The cost of the vaccine will vary according to veterinary practice and geographic location. Generally, the vaccine costs approximately $20 to $55.

If your veterinarian performs a physical exam before administering the vaccination, expect to also pay for the cost of the office visit. The vaccine and office visit together could cost upwards of $100.

Low-cost vaccine clinics provide an inexpensive option to get your dog vaccinated. Contact your local low-cost vaccine clinics to ask whether they have the canine influenza vaccine.

Does Your Dog Need the Flu Shot?

That depends. Here are some factors that increase a dog’s risk of getting the dog flu:

• Traveling extensively
• Going to doggie daycare
• Staying at a boarding facility
• Frequently visiting the dog park
• Participating in social events, such as dog shows and agility events

In older dogs, respiratory disease and heart disease can increase the risk of getting the dog flu. Also, brachycephalic (smoosh-faced) breeds are at higher risk of canine influenza because their facial structure makes it harder for them to breathe.

Talk with your veterinarian if you’re unsure whether the flu shot is right for your dog.