The Irreverent Vet Speaks out on “Does Your Dog Need the H3N8 Dog Flu Vaccine?”

The canine flu virus has been around for a few years. Actually, the virus received national media attention after Dr. Crawford and his colleagues published an article in the September 26, 2005 edition of Science Magazine entitled “Transmission of Equine Influenza Virus to Dogs”. The virus was brought to the forefront of Internet and national news in 2009 when it was discovered that the virus was causing illness and death in dogs at Florida Greyhound tracks and spreading to other dogs across the country. The first reported case was in Florida in 2003.

“Does my dog need the H3N8 dog flu vaccine?” This is a question commonly asked by dog lovers everywhere. Dog lovers want to do the right thing and protect their dog, but at the same time they want to minimize the risk of complications and avoid unnecessary expenses.

In this article, I’d like to address this question. I’m the Irreverent Veterinarian. I give you my opinion and speak the truth whether pet owners or other veterinarians like it or not.

The question that I’ll address today is, “What vaccines do dogs really need?”

Let’s start by taking a closer look at a few common questions about the canine flu virus.


Does the Canine “Flu” go by any other names?

The canine flu virus is also known as Canine Influenza Virus, Greyhound Disease and Race Flu.

What is the Canine Flu?

It is a highly contagious respiratory infection of dogs.

What are the Symptoms of Canine Flu?

The virus can cause coughing, sneezing, high fevers, nasal discharge, eye discharge and/or a fatal pneumonia.

What Dogs Will Develop the Infection?

It has been suggested that 80% of dogs exposed to the virus will develop an infection. Most dogs will only have mild coughing, however puppies and older dogs are at greatest risk for fatalities associated with the virus. The number of dogs at risk of dying from this virus may be anywhere from 1 to 10%.

The disease is associated most often with dogs housed in a high-density population or boarding kennel. The virus has been primarily documented in shelters, veterinary clinics, boarding facilities, pet stores and dog tracks.

Where Has the Canine Flu Been Found?

Every state in the continental U.S. except for one has either had confirmed cases of canine influenza or borders another state that has had a confirmed case.

How Is the Canine Influenza Virus Spread?

The infectious agent is transmitted by direct contact with respiratory secretions through the air or by contact with contaminated surfaces. When people use the same objects between infected and uninfected dogs, the objects become contaminated and the infection spreads.

Once a Dog is Exposed, How Long Before He Gets Sick?

The incubation period (time from exposure to symptoms) is estimated to be 2 to 5 days.

Can the Virus Spread to Humans?

There is no evidence that the dog virus can spread to humans, cats or other animal types. So far, it is believed that the virus is species specific and only spreads dog to dog. However, it is believed that the canine influenza virus is an influenza A H3N8 influenza virus that was originally a horse virus. The H3N8 equine virus has been known to exist in horses for 40 years. It is believed by scientists that the virus adapted from horses to cause illness in dogs.

How Can You Prevent the Canine Flu Virus?

There are a few things you can do to prevent the virus. Minimize exposure to infected dogs. Vaccination also helps prevent the virus.

To prevent infection, minimize exposure to other pets, especially in high-density situations such as kennels, doggy parks or puppy classes. Make sure your pet is kept away from any symptomatic coughing dog. Take special care if your dog is a puppy or a senior as dogs in these age brackets are at higher risk for difficult infections. The virus is spread through the air by infected dogs, through contamination of objects in the environment and by people that may interact with infected and uninfected dogs.

Because the virus is spread by air, avoid being around dogs that are coughing. This is the best prevention at this time.

Can You Kill the Virus?

The virus is killed by routine disinfectants such as quaternary ammoniums or a 10% bleach solution. Thorough cleaning of crates, cages, bowls, bedding, floors and other surfaces is recommended to prevent transmission to other dogs. Clothing, equipment, surfaces and hands should be cleaned and disinfected after exposure to dogs showing signs of respiratory disease to prevent transmission of infection to susceptible dogs. People interacting with infected dogs are advised to wash their hands well before and after interacting with infected dogs. Using a typical laundry detergent at normal washing temperatures will effectively clean clothing.

Now, for the real question pet owners want to know. “Does my dog NEED the vaccine?”


There is currently a vaccination available for canine influenza virus.

To consider if your dog needs the vaccine, it is important to first understand the vaccine’s benefits, which are similar to the benefits of other “flu” vaccines including human vaccines. This means that it is not a 100% effective way to prevent the flu infection but the vaccine still has benefits.

The vaccine is intended to help control virus infection and spread. The vaccine may not totally prevent infection in all dogs. What it will do is reduce the severity of the disease, reduce the duration of the clinical illness and reduce lung damage. The vaccine has also been shown to reduce the amounts of virus shed as well as the duration of the virus shedding.

Vaccinated dogs develop less severe illness and are less likely to spread the virus to other dogs. That’s the bottom line.

The vaccine is recommended for dogs “at risk” – dogs that frequently interact with other dogs, participate in activities with other dogs and dogs that are boarded.

Dogs that benefit from the kennel cough vaccine (Bordetella/parainfluenza) will also benefit from the canine influenza vaccine.

The vaccine is killed virus, recommended for dogs over 5 weeks of age. Recommended vaccination is two 1 –mL doses given 2 to 4 weeks apart. Annual revaccination with one dose is also recommended.

My Final Thoughts – What Vaccines Do Dogs Really Need?

So, does your dog “need” the vaccine? If you kennel your dog, go to the dog park or if your dog commonly interacts with other dogs then yes, I think the canine influenza vaccine is beneficial. If your dog is not boarded, is mostly in the house or doesn’t interact much with other dogs he probably doesn’t need it. With that being said, vaccination could be beneficial if he were to be exposed and may help prevent the spread if this very contagious disease.

You should discuss all vaccination programs with your veterinarian. Follow your veterinarian’s recommendations based on your dog’s personal risk.

If your pet begins coughing, call your veterinarian immediately to discuss recommendations for care.


The Irreverent Vet is a columnist that regularly contributes to to add a balanced and alternative view of some controversial pet issues. Most of the time veterinarians can’t say what they really think without offending some clients. This commentary allows vets to truly speak their mind and it gives you, the pet owner, the opportunity to consider another point of view. All opinions are those of the Irreverent Vet. They are not necessarily the views of and are not endorsed by