Dogs at higher risk of contracting heartworm disease from mosquitoes in OC, officials say

GARDEN GROVE, Calif. (KABC) -- The chances of dogs catching heartworm disease in Orange County are going up thanks to the Aedes aegypti mosquito, officials say.

The pesky Aedes aegypti, more commonly known as the ankle biter, is behind more than the persistently itchy welts on our legs.

Heather Hyland with the OC Mosquito and Vector Control District said Thursday that results from testing at the end of 2021, show that this species of mosquito carries heartworm, which can be fatal to our furry friends.

"Out of 260 samples, we found that four tested positive for dog heartworm detection. That's telling us that there is dog heartworm in the community, but it's also telling us, based on that data, that it's low-risk right now," Hyland said.

According to a 2019 map from the American Heartworm Society, no state is heartworm free. The darker the red, the higher the number of cases. The map shows Mississippi and Louisiana leading the country in infection rates.

The mosquitoes testing positive in Orange County came from Huntington Beach, Seal Beach, and Fullerton. The danger in Southern California is that ankle biters are rapidly breeding, and they can spread heartworm to dogs with just one bite.

Many dogs don't show symptoms in the early stages, but by the time there are hundreds living in the host's heart, lungs and blood vessels, symptoms can include a mild persistent cough, reluctance to exercise, fatigue after moderate activity, decreased appetite, weight loss and a swollen belly.

Hyland says prevention is key. Protect your pets with heartworm preventatives from your veterinarian and don't let these bugs breed. They need still water to reproduce, so get rid of these sources.

"I like to call them the backyard breeder. They prefer to breed in tiny containers in people's backyards, even in apartment complexes. You're going to see that they are laying eggs around the rims of saucers," explained Hyland.

Hyland said dog flea and tick topical medication also helps repel mosquitoes.