DC ranks 2nd in top 10 cities for prevalence of heartworms in pets

The D.C. area ranks second in the nation out of 200 metropolitan cities examined for cases of heartworm disease among pets, according to a report by the Companion Animal Parasite Council.

Washington comes in behind Moreno Valley, California, on the list and above Newark, New Jersey, Indianapolis, Indiana, and Cheyenne, Wyoming, in the top five.

Craig Prior, past CAPC president, says that the organization has seen a 20% rise in cases of heartworm disease nationally in the last five years.

“When we’re seeing these spikes in the prevalence rates in places like D.C. and other areas where you normally won’t see large numbers of heartworms, we realize that there’s something going on here that you need to be aware of and that you need to talk to your veterinarian because your dog has got the potential to be exposed,” said Prior, who has been a veterinarian for more than 35 years.

The CAPC states that the transportation of rescue dogs from southern states is part of the migration and increase of heartworm cases in areas that normally don’t rank high on the list.

Some of these are dogs relocated from the south due to hurricane relief who may not have been tested or treated for heartworm disease.

“Less than a third of them are being tested for heartworms, let alone treated,” Prior said. “These dogs are being transported into new areas where the heartworm hasn’t been an epidemic, and they’re being adopted out.”

He adds that while owners are urged to take their newly adopted pets to the veterinarian, they often aren’t taken for a couple of weeks to a year, which can be dangerous when it comes to spreading diseases.

“These dogs are now in someone’s backyard, and if you look at the mosquito, which is the insect that spreads it, there’s over a dozen species that will transmit heartworms, and the average mosquito’s range is anywhere from 150 yards out of that infected dog to a mile and a half. So that dog is suddenly a source of potential exposure or infection for every dog in that neighborhood,” Prior said.

Heartworms look like “strings of spaghetti” that can measure from 12 to 14 inches long and can live in a pet’s lungs and heart. The worms reproduce offspring called microfilaria that float in the bloodstream. When a mosquito bites an infected animal, it can pick up the microfilaria that is then spread to uninfected dogs through a mosquito bite.

Symptoms of heartworm disease in dogs include lethargy, coughing, exercise intolerance, and, in more serious cases, a swollen abdomen and organ failure.

In cats, symptoms include lethargy, vomiting and sudden death.

Prior says that the solution, though, is simple.

“We can just give it one little pill once a month or an injection, or we’ve got topical preventives as well that you can put along the back of the neck and it will prevent that pet from getting heartworms,” Prior said.

Getting rid of standing water in the yard also helps, as they can become breeding grounds for mosquitos. Prior says that 26% of indoor cats will contract heartworms, demonstrating that it’s not only outdoor animals that are risk.

Preventative medicine will also protect from hook worms or round worms, which can occasionally spread to humans.

“There are 10,000 cases of round worms affecting children every year and it’s typically children with pets, and they’re getting them directly from their pets. It can cause blindness in children. So keeping your pet healthy keeps your family healthy,” Prior said.

Find more details on heartworm in pets and map forecasting the future prevalence of heartworm disease in your area and in areas you may be traveling to here.

WTOP’s Mike Murillo contributed to this report.

Valerie Bonk

Valerie Bonk started working at WTOP in 2016 and has lived in Howard County, Maryland, her entire life. She's thrilled to be a reporter for WTOP telling stories on air. She works as both a television and radio reporter in the Maryland and D.C. areas. 

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