Pet Health Alert: There is an ongoing outbreak of canine influenza (H3N2) in the Southeast associated with a dog show that was held in Georgia the weekend of May 19-21. News stories on the virus have generated multiple questions from area pet owners, some of which I will address in this column. As with everything you read here or anywhere else, it is wise to consult your family veterinarian for specific advice for your pet.

Q: What symptoms are caused by canine influenza?

A: In dogs the flu virus looks a lot like what it does in people. It causes persistent cough, fever, lethargy and reduced appetite that typically last for a week or two. It can also cause nasal or ocular discharge. Much less commonly, serious life-threatening pneumonia can develop. The fatality rate of canine influenza is less than 10%.

Q: How contagious is it?

A: Very contagious. When exposed, about 80% of dogs will contract the virus. An affected pet is contagious for up to four days prior to showing symptoms and up to three weeks after symptoms start. Cats are less susceptible, but can contract one strain of the virus, too. So far humans have not contacted the dog flu, but public health experts still warn to limit contact as much as possible with infected pets – especially infants, the elderly, or those with immune compromise due to illness or medications.

Q: What is the difference between the strains?

A: The H3N8 is not new. It was discovered in 2004 and has occurred sporadically throughout the country, often associated with greyhound racetracks, animal shelters, or public dog parks. Typically, a handful of cases will pop up in a localized area and then the “outbreak” will die out.

H3N2, or “the new strain,” was discovered in 2015 in the Chicago area. So far it has been much more geographically limited, but It is also much more persistent and more readily spread. The Chicago outbreak extended into neighboring states and still generates new cases now, although at a much lower rate than two summers ago. Until last month, H3N2 has only sporadically occurred throughout the rest of the country, almost always after exposure to a dog from the upper Midwest.

As I write this week’s edition (several days before you read it), the current outbreak has affected dogs in Georgia, Florida, and Tennessee. So far, no dog has ever tested positive for H3N2 in Virginia. However, since the H3N2 strain is now active along both the I-95 and I-81 corridors, veterinarians in Virginia are on the lookout for its arrival in our state.

Q: Does my pet need to be vaccinated?

A: The answer to this question depends on your pet’s lifestyle. It would be appropriate to vaccinate dogs that will be in contact with dogs from the affected areas due to travel or participation in dog shows or other events. If you plan to leave your pet in a boarding facility that may house exposed pets, it would also be wise to consider vaccinating your dog. It is important to note that the vaccine is labeled for reduction in severity of symptoms, not to completely prevent infection with the virus. The best protection is to keep your pet at home or in outdoor spaces away from dogs that you don’t know.

There are no vaccines for cats, but there are three different types of vaccines for dogs. One is for the H3N8 strain of the virus. Another is for the H3N2 strain. The third is a bivalent vaccine, meaning it contains both strains. Initial vaccination requires two doses, spaced three weeks apart. Inoculation reaches peak effectiveness over a week after the second vaccine, so the series should begin at least a month prior to anticipated exposure. An annual booster vaccine is required to maintain protection.

Q: Where can I get more information?

A: The American Veterinary Medical Association has an excellent canine influenza web site that also includes links to many other good sources of information. You can visit the AVMA’s information page at

I will continue to monitor the current outbreak and post updates to Of course, the best source of up to date information and advice is your family veterinarian.