Princeton Veterinary Hospital

Canine Influenza: What do you need to know?

What is Canine Influenza?

• Canine influenza is a newly emerging infectious disease caused by a “flu” virus.  In dogs, a highly contagious strain of the influenza A virus known as H3N8 is able to cause respiratory illness.  Other strains of the influenza A virus are responsible for causing infections in brids, horses, pigs, and people.  Canine influenza virus only affects dogs.  Currently 30 states have reported cases of canine influenza (the virus was first reported in Florida in March 2003).  At this time, Indiana has not yet had a confirmed case of canine influenza, however, the vaccine is now available at our clinic to help prevent spread of the contagious disease.

How contagious is canine influenza?

• Just like human “flu,” canine influenza is highly contagious.  In fact, unless a dog has already had the illness and recovered, virtually every dog exposed to the virus could become infected.  While 100% of dogs are susceptible to influenza infection, about 80% of infected dogs will show signs of infection.  Dogs that do not show signs of the disease can still spread the virus to other dogs.
• Since 2003, there have been numerous reports of influenza outbreaks in veterinary clinics, kennels, and shelters.  Some of these outbreaks were traced back to the presence of one sick dog that spread the virus throughout the facility and infected many other dogs.
• Canine influenza is usually mild but can become quite serious in some dogs.

What are the signs of canine influenza?

• The most common sign is a persistent cough.  Some dogs have a soft, moist, “productive” cough, while others have a dry cough similar to that seen in dogs with kennel cough (caused by any of a number of other viruses/bacteria).
• About 80% of dogs who show signs will have mild disease.  Signs in this case include: low-grade fever (102 to 104 degrees), nasal discharge, lack of energy, loss of appetite, and a cough that can last for up to a month.
• In about 20% of dogs, more severe signs will occur, such as a high fever (104 to 106 degrees) and pnuemonia.  A small number of dogs infected with the virus have died from complications associated with the disease.

Is my dog at risk for infection?

Most dogs, regardless of breed or age, are at risk for canine influenza.  However, certain locations or activities can raise your dog’s risk of infection.  Review this list of questions to see if any of these places/activities apply to your pet.

Does your dog:

• Come from a shelter, rescue center, breeding kennel, or pet store?
• Board at a kennel or go to doggie daycare?
• Attend group training or “dog kindergarten”?
• Visit a groomer, dog park, or engage with other dogs on daily walks?
• Enter dog events?
• Come into contact with other dogs in the waiting room during visits to your veterinary clinic?

If you answered “YES” to one or more of these questions, ask us what can be done to protect your dog from canine influenza.

How is canine influenza spread?

Canine influenza is spread the same way that human flu spreads – through direct contact (kissing, licking, nuzzling); through the air (coughing or sneezing); and via contaminated surfaces. 

How can I protect my dog from canine influenza?

Protection starts by keeping your dog in good general health.  A well-nourished, well-rested, and well-cared-for pet will have a stronger immune system to help fight off infection.  Recently, a new canine influenza vaccine – the first of its kind – was approved for use in the US.  The initial vaccination requires 2 doses, 2-4 weeks apart, followed by annual revaccination.