Heartworms are a serious and potentially fatal disease that mainly affects dogs, cats and ferrets. It is caused by the parasitic worm Dirofilaria immitis, which infects pets through the bite of an infected mosquito.
In dogs, once the heartworms mature, they travel to the heart, lungs and arteries, then mate and produce offspring, increasing the number of worms that the dog carries over time. These worms cause damage and scarring to these vital structures which can affect their overall health and the quality of life of the animal the longer they go untreated. If left untreated, the complications can eventually lead to heart failure, permanent lung damage and death.