Dear Daisy Dog
My dog and cat take medicine every month to prevent heartworms. What about me? Can humans get heartworms?
Yes, but it’s rare.
Heartworms are transmitted by mosquito bites. Dogs, cats and about 30 other animal species can become infected and develop serious, life-threatening disease.
That’s because heartworms damage the heart, lungs and blood vessels.
Unfortunately, we dogs are natural hosts for these parasites, so after a mosquito bites us and injects infective heartworm larvae into our bodies, we develop adult heartworms.
Cats are better able to resist heartworm disease, because their immune systems kill some of the larvae before they mature into adults. (Please don’t tell Christopher Cat, who always brags that cats are superior to dogs.)
You humans are even better at resisting heartworm infection than cats, because you are not natural hosts for the parasite.
Only rarely does a heartworm infect a human. When it does, your lung tissue walls off the parasite.
Therefore, most people have no symptoms. However, some patients experience chest pain, cough, fever or breathing difficulties.
Their chest x-rays show a small lung mass that looks like a tumor. When it’s removed, it’s only the dying, walled-off heartworm.
Unfortunately, scientists have not developed a reliable diagnostic test for heartworms in humans – and a monthly preventive like the one your pets take is not available.