Can a dog pass on heartworm to another pet or person?

Indirectly, yes. It's not like if a dog with heartworm disease touches another dog that they'll instantly pass that heartworm disease. But the adult heartworms are producing larval or baby heartworms. We call that microfilaria that can be picked up by a mosquito and transmitted to another pet.

Good question. No, they cannot. It is kind of interesting. I'm going to give a little bit of inside here. A lot of times when dogs come in, and we do a heartworm test, one of the things that I often ask as I'm getting the blood sample is if that particular pet parent happens to know how dogs get heartworms. Most of them don't know. Most people don't know how dogs get heartworms even though they're giving their medication to their dog on a monthly basis or getting the six or 12-month injection. It makes me realize that, somehow, as a profession, we have failed to educate people about this importance. I think people understand the importance of it, but it's more important to recognize how they get them in the first place because this gives you a sense of why it is a problem and a continual problem, particularly in the southeast part of the US. Quite simply, how do dogs get heartworms? Only from mosquitoes. So they cannot pass it to people. They cannot give it to another dog. Only mosquitoes can transmit heartworms from an infected dog to a dog that's not currently on heartworm prevention. That's it. Mosquitoes. That's the only way it can be spread.

Not through direct transmission, but they do utilize the mosquito. The mosquito bites an infected dog, and it is then reproduced in the mosquito and passed onto another dog. It is extremely rare to find heartworm disease in humans.

No, a dog cannot pass on heartworms directly to another dog or a person. It requires a mosquito to bite the infected dog, get the infected larva, and then bite another dog, depositing the infected larva for it to be spread. Heartworm disease is not spread to humans.