23 / Apr What Every Pet Owner Needs to Know About Heartworm What is Heartworm? Heartworms are roundworms or nematodes, which spread to dogs via mosquito bites. Mosquitos inject immature worms into the dog’s skin, which then emigrate over time to the blood vessels around the dog’s heart. This is why the disease is called heartworm –... Post by Alex Barratt - 0 comment