Feline Heartworm Disease

Most people are not aware that cats are susceptible to heartworm disease. Although heartworms are primarily found in dogs, they can infect a wide variety of mammals including ferrets, sea lions, bears, foxes, wolves, coyotes, cats, and humans.

Heartworms are caused by a parasite called Dirofilaria Immitis. The adult heartworm resides in the heart and major arteries of the lung. They are transmitted from an infected host by mosquitoes. The mosquito bites an infected animal and transmits a tiny, microscopic immature heartworm called a microfilaria. The microfilaria are found in the blood stream of infected animals. The microfilaria while in the mosquito, develops into an infective larva. The mosquito then transmits this larva to another animal when it bites another animal. The larva will then migrate through this animal and mature into adult worms in the heart or major arteries of the lung. In cats, the adult heartworm lives for one to two years, and it is unusual to find more than one to three heartworms. Even though there is only a small number of worms in the cat, they can still cause serious health problems.

Clinical signs in the feline are variable. Some infected cats may show no signs of disease at all. Others may have chronic coughing, wheezing, difficulty breathing, vomiting, or even sudden death. There have been many documented cases of what seemed like perfectly healthy cats one minute and the next they just suddenly died. Feline heartworm disease can be diagnosed by blood tests, chest radiographs (x-rays), and ultra sound of the heart and lungs. Unfortunately, treatment to remove heartworms in cats found to be positive is difficult and hazardous to the cat. There are medications available from your veterinarian that will help to minimize the symptoms of the disease. The best way to protect your feline friend is by giving them a monthly heartworm preventative. This oral medication is effective in preventing this disease by stopping the migrating microfilaria as it matures in the body. You should consult with your veterinarian on the prevention and management of feline heartworm diseases.

Presented by Dr. Jan Hasse at Sarasota Animal Hospital (941) 371-5951