Heartworm disease is caused by a parasitic worm called Dirofilaria immitis. This parasite is transmitted primarily through the bite of infected mosquitoes, not directly from dog to dog. When a mosquito bites an infected dog, it takes in the heartworm larvae, which then mature and become infective within the mosquito. When that mosquito bites another dog, the infective larvae are transmitted, potentially leading to heartworm disease in the new host. However, it's important to note that while dogs cannot directly transmit heartworms to each other through contact, the mosquitoes that carry the disease can bite multiple dogs, effectively spreading the heartworm larvae from an infected dog to others in the vicinity. In summary, heartworms are not passed directly from dog to dog, but through the intermediate host, the mosquito. It's crucial for dog owners to be aware of the risk and to take preventative measures, such as administering monthly heartworm preventative medication and having regular check-ups with a veterinarian. read more >>

A: It can only be passed on by mosquitoes. It's a specific parasite that only affects dogs and cats and ferrets and other mammals. In rare cases, heartworms have infected people, but it does not complete its life cycle. The heartworm will migrate to the lung and cause a round lesion that looks like a tumor.read more >>