Heartworm disease as a serious parasitic problem that, left untreated, causes heart failure in dogs and cats. This disease is exactly what it sounds like, worms set up shop inside the heart. These worms live in the pulmonary artery, which causes an obstruction of blood flow into the lungs and severely dilates the heart muscle due to pulmonary hypertension. So, how do worms get into the heart? Blame the mosquito. Mosquitoes carry the heartworm larva and inject the larva into the animal’s body when feeding. The larva will mutate several times and migrate into the bloodstream. Once they reach the heart they mature and reside in the pulmonary artery. In what areas is heartworm disease a problem? Any place where mosquitoes and a canid reservoir population are in the same place. That covers a lot of the country. What about San Diego? While not a severe problem, there are heartworm cases diagnosed locally every year. It is estimated that 20% of the coyote population is heartworm positive.
Heartworm disease is a condition that is much easier to prevent than to treat. The American Heartworm Society recommends year-round heartworm prophylaxis. Preventative options include monthly oral or topical treatments or a 6 month duration injectable. A simple blood test will determine your pet’s heartworm status. A negative test means that dog can safely start prophylactic care.
The symptoms of heartworm disease include mild persistent cough, reluctance to exercise, fatigue, and weight loss. These signs will eventually lead to congestive heart failure and cardiovascular collapse. Heartworm disease can be contracted by cats but because cats are not a natural host the disease course can be more severe and with a smaller worm burden.
Prevention of heartworm disease is important and you should talk with your veterinarian regarding your pet’s status.