This disease is contagious

Even though heartworm disease is often called a “virus”, due to the confusion created by the fact that the animals become infected (so there is practically an infection in their body), it doesn’t make this disease contagious, or at least not directly between mammals.

“Heartworm is spread through a mosquito [that bites and] acquires the heartworm larvae from other infected dogs, coyotes, wolves or foxes,” Dr. Hatton says. “The infected mosquito then bites a dog or cat and transmits the immature worms to them. If not on heartworm preventive, the larvae mature and multiply, causing damage to the heart and lungs.”

According to experts, there are very rare cases of humans contracting this disease. “Humans are considered [to be] dead-end hosts. It’s extremely rare for humans to get heartworm disease, but they can be exposed to heartworm disease through the bite of a mosquito and end up with lung pathology and granulomas in various organs,” Dr. Hatton says.