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Pets: Protect your dog from the flu

Veterinarians were overwhelmed with an epidemic of the dog flu in the Chicago area (including Northwest Indiana) this past spring.

Veterinarians quickly realized this flu strain is different than the dog flu first discovered in the U.S. in 2004, and identified it as new flu strain, H3N2. Oddly, it’s a strain of flu that arrived in the U.S. from Southeast Asia.

Of course, dogs travel and soon the virus spread – ultimately to about half the country.

At the height of what was called an epidemic, this past spring and summer, it’s estimated that at least a thousand dogs in the Chicago area were sickened, and at least eight dogs died.

While the epidemic in Chicago area has subsided, the H3N2 strain of dog flu is still occurring in the Windy City and elsewhere. The most recent outbreak is ongoing in Austin, Texas. In all at least 50 dogs across the country have tested positive for H3N2 this month. Having said that, a considerable number of pet owners decline testing due to the cost or simply because they feel treatment is going to be the same anyway.

A Merck Animal Health survey discovered that 71 percent of stricken dogs were 1 to 7 years old, and that day care and boarding facilities were the potential infection source in eight out of 10 cases.

Still, avoiding the dog flu can be challenging, since about 20 percent of dogs carrying the virus exhibit no symptoms, but are contagious. Even if dogs are “antisocial,” they can still get the virus from being where other dogs have been, such as elevators in high-rise buildings.

Dr. Justine Lee, emergency and critical care specialist in St. Paul, Minn., says there is only one sure way to avoid the virus, and that’s to be vaccinated with the new vaccine specific for H3N2. Lee answers some of your dog flu questions:


Q: Living so close to Chicago, but not that close, do I need to get our dog vaccinated for the dog flu?

– C.K., Kenosha, Wis.

A: “The dog flu is occurring in states further away from Chicago than Wisconsin,” says Lee. “And the dog flu has been identified in Wisconsin. Whether the vaccine is a good idea for your dog depends on what your veterinarian is seeing. However, if you travel to Chicago, or your dog is in day care or boarded with dogs potentially from the Chicago area, I’d say your dog is at more risk.”

Lee says that while the virus isn’t seasonal, boarding is a significant factor in spreading the flu. No matter where you live, if you are boarding your dog, Lee says to consider the vaccine.


Q: I did get my dog vaccinated for the original dog flu. Do I need another vaccine for this strain?

– F.F., Chicago

A: “We do continue to have an effective vaccine for H3N8, the strain of flu discovered in 2004,” says Lee. “We don’t yet know how protective that vaccine is for the (newly discovered) H3N2 strain. However, we do know the new vaccine specifically for H3N2 does protect against H3N2.”

Both are annual vaccines, and include an original shot followed by a booster vaccine 14 days to a month later. In some cases, the vaccine prevents flu, or in others cases lessens severity of symptoms. And symptoms of H3N2, in particular, may be significant, as many of the sickened dogs required hospitalization.

Dr. Melissa Bourgeois, senior specialist at Drug Safety Companion Animal Pharmacovigilance at Merck Animal Health, says the H3N8 and H3N2 vaccines should not immunologically interfere with one another. However, for some dogs (with a history of vaccine reaction) getting one shot at a time might be a good idea.


Q: I don’t understand how many – if any – dog flu vaccines my dog needs. I don’t know any report of any dog flu in my area. And my veterinarian says, “don’t worry about it.” But I still worry a little.

– C.P., Buffalo, N.Y.

A: Your veterinarian is correct – there should not be panic in the streets. “However, once the H3N2 virus hits an area, it’s easily spread, in part because dogs without symptoms can spread the virus for 21 to 28 days,” Lee says.

At the end of the day, the only surefire defenses are either to stay away from other dogs and where other dogs have been, or to vaccinate.

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