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Pets: Vaccines available for dog flu

Q: The dog flu hit our family hard; we have all recovered, but we sure don’t want to go through that again. Will there be a vaccine, and if so, when? – D.S., Chicago

Q: I need a dog flu vaccine now to feel comfortable going out with our dogs. Steve, you promised that by 2016 there would be a vaccine. Well, it’s almost 2016. Do you have an update? – S.H., Atlanta

A: I’ve received hundreds of similar questions. The good news is that at the end of this year, vaccines specifically to fend off the new potentially dangerous strain of canine influenza virus, which appeared in America the first time in 2015, will be available.

It all began in Chicago this past spring when veterinarians were overwhelmed by dogs sickened with an unidentified respiratory disease. Veterinarians quickly discerned this wasn’t run-of-the-mill respiratory illness; the virus was identified as dog flu. But veterinarians were mystified because this flu seemed to be acting differently and often making dogs sicker compared to H3N8, the dog flu previously seen in the U.S.

Scientists, including those at IDEXX (the veterinary diagnostic lab) quickly found the needle in the proverbial haystack – somehow recognizing that the dogs were getting sick from H3N2, a strain of dog flu common in Southeast Asia, but never previously seen in the U.S.

From Chicago, H3N2 hit sporadically across the country – in some places harder than others. Chicago, though, had the worst of it, a real epidemic. Thousands of dogs became ill, many requiring hospitalization. And eight dog deaths were confirmed to be caused by H3N2, though there were likely more, according to Cook County Veterinarian Dr. Donna Alexander.

Dr. Eileen Ball, Zoetis U.S. Companion Animal Veterinary Operations Veterinary Medical Lead/Biologicals and Infectious Diseases, explains that the new vaccine targeting H3N2 was created rapidly with cooperation of the U.S. Department of Agriculture, which allowed for essentially swapping out the N8 antigen from the existing dog flu shot with the specific N2 antigen so antibodies can be produced against it for vaccinated dogs.

Ball says it remains unclear how protective the H3N8 dog flu vaccine may be for the H3N2 strain, “It was thought to be in the best interest of dogs to do something, which we know will work, and get it to market quickly.”

However, it’s important to understand that H3N8 hasn’t disappeared – so for many dogs both vaccines are suggested.

Dr. Melissa Bourgeois, senior specialist at the Drug Safety Companion Animal Pharmacovigilance at Merck Animal Health says the H3N8 and H3N2 vaccine 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. Both dog flu vaccines require a booster 14 days to a month after the initial shot.

“For social dogs, the benefits (of both vaccines) far outweigh any risks,” she says. “The H3N8 canine influenza virus is not the most common respiratory disease in dogs, but it’s the deadliest, with about an 8 percent mortality rate. We don’t yet have all the data regarding H3N2, but we know dogs get sick for a longer period of time.”

Anecdotally, some veterinarians have suggested that more dogs become more ill from H3N2 compared to H3N8.

In any case, dogs up all night coughing – as often occurs – impacts the entire family’s quality of life.

Bourgeois explains the dog flu isn’t seasonal, per se, but instead just suddenly appears.

Talk with your veterinarian about whether the dog flu vaccination is a good idea for your dog.

Steve Dale welcomes questions/comments from readers. Although he can’t answer all of them individually, he’ll answer those of general interest in his column Send email to petworld@steve dale.tv. Include your name, city and state. Steve’s website is stevedalepetworld.com; he also hosts the nationally syndicated “Steve Dale’s Pet World” and “The Pet Minute.”