Introduction to heartworms
Heartworms (Dirofilaria immitis) are dangerous, potentially fatal parasitic worms transmitted through infected mosquito bites. Heartworm disease has been reported across the country, primarily affecting dogs--although cats, ferrets, and some other mammals are also at risk for infection. Heartworm disease can be easily prevented in dogs and cats with regular applications or pills, but it can be difficult to diagnose and very costly to treat.
Heartworms do not infect humans.
You are completely safe from contracting heartworm disease. Your pet cannot infect you--only mosquitos can create the right environment and incubation to spread the heartworm larvae.
And even being bitten by an infected mosquito would not give you heartworms or any symptoms of illness. People are not a natural host for heartworms, and because of our immune systems, we are not conducive to their survival. It would be extremely rare for the bite of an infected mosquito (who has fed on an infected animal and incubated the larvae) to pass the heartworm to a human host. And in the rare instances where heartworms have infected humans, they die before their life cycle can complete. Harmful adult worms never have the opportunity to form in humans.
In a few instances, a human infected with heartworms has been diagnosed with a lesion or small tumor on the lungs. This is believed to be a result of heartworm larvae dying in the lungs and setting off an immune response. But even in these rare cases, no evidence indicates heartworms are harmful to humans.
Some other pet parasites, however, can infect humans. Check out our other parasite and worm fact pages for more information.
More on Pet Parasites
5 Things You Need To Know About Roundworm
What To Do When Your Pet Gets Tapeworm
Using Panacur Granules for Parasite Infections
This information is for informational purposes only and is not meant as a substitute for the professional advice of, or diagnosis or treatment by, your veterinarian with respect to your pet. It has, however, been verified by a licensed veterinarian for accuracy.