Heartworm Not only a Summer Threat for Pets

As temperatures decrease, the risk for heartworm does not.

Heartworm, a serious disease caused by a parasite, affects dogs and cats across the United States. Typically, heartworm is transmitted from mosquito bites (but rarely affects humans) during hot summer months.

“Heartworm is endemic in many parts of the United States, due to conditions that favor the proliferation of mosquitoes that carry the disease and the high reservoirs of animals carrying heartworm larvae,” says the American Heartworm Society president Wallace Graham, DVM. Meanwhile, he adds, the mosquitoes that carry heartworm disease breed in standing water, and late-summer weather events such as hurricanes and heavy storms have left plenty of standing water in their wake.

If you are a pet owner, here are additional facts you should know about heartworm disease:

  • Heartworm is everywhere.  According to a nationwide survey of more than 5,000 veterinary hospitals conducted by AHS in 2010, heartworm was confirmed in all 50 states.
  • Cats get heartworm disease, too.  Dogs are more susceptible than cats, but cats can become seriously ill from just a few worms. The bottom line: if you live in an area where heartworm disease in dogs is present, your cat should get preventive medication, too.
  • Treatment is not a “fallback.” While heartworm disease in dogs can usually be treated, veterinarians have limited medication supplies, the treatment carries risks (careful monitoring and cage confinement are required for a month or more) and treatment can cost as much as $1,000. Meanwhile, there is no effective medication for treating cats with heartworm disease.
  • Heartworm actually affects the lungs of animals, but may travel into the heart in severe cases. Blindness, seizures, lameness, coughing, and lethargy are common symptoms of heartworm. If your pet exhibits any of these symptoms, seek veterinary attention immediately.


For more information on the AHS, go to http://www.heartwormsociety.org/.