Pet-refugees bring infections

Of the thousands of pets left behind during Hurricanes Katrina and Rita, many of the survivors that weren’t later reunited with their owners have since been adopted around the country.

Yet, the fresh start these animals now enjoy may inadvertently cause heartache for their new families. An estimated 60 percent of the dogs and some of the cats displaced by Katrina are likely infested with heartworm a potentially fatal, mosquito-borne illness.

In people the disease is rare and causes only nonfatal lung lesions sometimes mistaken for lung cancer on an X-ray.

Logically, the vast majority of pet heartworm cases throughout the country have been found where the mosquitoes are – in the wet and humid climates. But because of all the recent pet-refugees from hurricanes, some veterinarians worry this insidious killer could begin making inroads into low-incidence areas like California, other Southwest states and the Pacific Northwest.

My nephew Jim Burkholder III and his wife, Christina, of Portland, adopted a Katrina dog named Lila and got two surprises.

Lila was severely infected with heartworms – and pregnant. Lila had nine puppies!

Jim and Christina found good homes for eight and a great home for the one puppy they decided to keep.

Dr. Tom Nelson, president of the American Heartworm Society, says it’s too early to tell whether refugee dogs will spawn significant heartworm outbreaks in other regions. Areas that are not conducive to large mosquito populations are less likely to see heartworm outbreaks.

Animals cannot be accurately diagnosed with heartworm for at least six months after infection, he says.

Any adopted pet should be tested immediately, then put on preventive, and tested again a year later because of the lag between infection and detection.

A special protocol for these superstressed hurricane refugee dogs was developed by Nelson; Dr. Kate Hurley, director of shelter medicine, University of California, Davis; and Dwight Bowman, a professor of parasitology at Cornell University. It recommends pre-treating heartworm-positive animals with the standard heartworm preventive medication before killing the adult worms in stages several months later.

“These dogs are so weak and stressed that many just can’t survive the full treatment right away,” Nelson said. “However, we have to stop the spread immediately.”

Bowman, one of the experts who helped draft the Heartworm Society’s treatment guidelines, said one silver lining from the Katrina crisis has been increased awareness about the dangers of heartworm.

“What this event has shown us is we need to get a lot more dogs on preventative medication,” Bowman says. “This disease is preventable using products currently available, so there is absolutely no reason for a dog to have 12 inch-long worms in its lungs.”

Since refugee dogs might be coming into your area, Nelson said, pet owners should play it safe and have their animals tested annually for the disease.

Simple oral or topical preventive treatments, administered once a month, can eliminate the risk in animals that do not test positive. The costs are low – a few dollars per month for dogs.

In contrast, the expense of treating the disease can run up to thousands of dollars, depending on the severity. Yet, the alternative is worse.

Left untreated, heartworm can be debilitating or fatal.

Nelson, a practicing veterinarian in Anniston, Ala., has seen dogs as young as 2 die from heartworm.

Don’t let this disease worm its way into your dog. Learn more by viewing the American Heartworm Society’s guidelines for treating heartworm at www.heartwormsociety.org.