Do I need to be concerned about the dog flu?

Q: Do I need to worry about the dog flu?

A: Last week the Fairfax County animal shelter experienced a localized outbreak of canine influenza. At least one case was also reported in a private practice in northern Virginia. Together with publicity surrounding the recent release of a canine influenza vaccine, many dog owners are beginning to worry about this virus.

The influenza strain affecting dogs, called H3N8, is not a human influenza virus. It is also not the H1N1 “swine flu” strain that has been in the news recently. No person has ever been diagnosed with “canine flu.” The H3N8 strain has been present in horses for over forty years. Four years ago, veterinary experts determined that the virus had developed the ability to spread into the canine population. Since then it has been documented in thirty states. 

So far, the infections have been localized and sporadic. The first infections were documented in association with racing Greyhound tracks. Other infections have centered around animal shelters. Currently, the virus is not moving rapidly through the general canine population.

Just like in people, the primary symptoms of flu are cough, runny nose, and fever. Over eighty percent of cases are mild, with some patients showing no noticeable symptoms at all.

However, a severe form that leads to pneumonia does exist. A small number of the severely affected dogs have died. The mortality rate is 1-5 percent with very young, very old, sick, or debilitated dogs more likely to experience life-threatening complications.

A canine influenza vaccine was granted a conditional license by the FDA this summer. The vaccine was studied in just over 700 dogs by the company marketing the product. The conditional license requires the vaccine to be administered under the supervision of a veterinarian. The FDA will continue to collect safety data in an effort to grant a full license at a later date.

When deciding to vaccinate against any disease, the risks associated with vaccinating must be weighed against the benefits. Since the vaccine is so new and has been administered to so few dogs, the risks are not very well defined at this time.

The potential benefits are also still emerging. Pets living in a home and staying in their yard or neighborhood probably have a very low risk of coming into contact with the virus. As we already discussed, the illness is generally mild when it is contracted. As such, I am not ready to recommend this vaccine for broad use at this time.

Dogs going to boarding kennels, groomers, dog parks, dog shows, or events do have a higher risk of being exposed to the virus. If there is a concern about a geriatric, neonatal, pregnant, or immune compromised dog in the household, I would consider limiting exposure to large groups of unfamiliar dogs. There are mobile groomers in the area that will come to your house. There are pet sitters and very small “pet resort” facilities that can care for your pet while you are away.

Any dog with a cough should be evaluated by a veterinarian. Any coughing dogs should be kept as isolated as possible to help prevent the spread of infectious disease. Operators of kennels, pet stores, training facilities, grooming shops, and other pet related businesses should take precautions to minimize disease transmission in their facilities.

I expect the number of cases in northern Virginia to be limited as it has been everywhere else the virus has occurred. It is likely that in a few weeks the “scare” will be over. In the meantime there is going to be more media and Internet hype about the dangers to your dog. I recommend resisting the urge to panic. Remember, we are talking about the flu - not cancer or the plague. While it can be serious in certain situations, most of us have had the flu and lived to tell about it.

More information on canine influenza can be found in the public health section of the American Veterinary Medical Association’s web site (avma.org/public_health) or from the Centers for Disease Control and Prevention (cdc.gov/flu/canine).

Dr. Watts is a companion animal general practitioner and owner of Clevengers Corner Veterinary Care. He can be reached through ClevengersCorner.com or by calling 428-1000.