Do cats get heartworms?

Heartworm is a deadly disease! Many animals have died from this kind of disease that is caused by a mosquito bite. Heartworm disease is more identified with dogs. As such many cat owners are not aware that their pets can get this fatal disease too. Although more common in dogs, cats are as well affected by heartworms. Compared to dogs, cats are more resistant to heartworm disease but the size of a cat’s heart makes these animals more vulnerable to the infestation. A few heartworms can already cause the cat’s death. Heartworms in dogs can be treated with medication. This parasite infestation is more difficult to treat in cats as the death of the worms could also mean the death of the cat. There is no acceptable treatment that will remove the parasites from infected cats. It is therefore imperative for cat owners to know about heartworms so that the disease can be prevented.

Dirofilaria Immitis or heartworm is a parasitic worm that is spread through mosquito bites. Dogs are the definitive hosts of these parasitic roundworms but cats and other animals are also infected. How is a cat affected by these parasites? Infection will begin with a single bite of a mosquito that has had a blood meal by biting an infected dog. The microfilaria (the early larval stage of the parasite) picked up by the mosquito from an infected dog would stay in the mosquito’s salivary gland for about 2 weeks until it becomes infective. The microfilaria will be injected through the little hole the mosquito makes when it bites the cat. Because cats are not the typical hosts of heartworm the infection rates are much lower as compared to infection rates in dogs. Cats are not as well adapted as dogs in harboring heartworms in their body thus the immune system’s response is to kill the larva before it is given a chance to develop. Cats will also try to stop the worms from travelling through the body by walling off the parasites so that the worms would form cysts in the cat’s kidney, liver, brain and other body parts. This is why heartworm infestation in cats would cause the development of other diseases other than the heart failure that occurs in dogs. Not all heartworm larvae will be killed and stopped…others will migrate to the lungs and to the heart. Although commonly known as heartworm, these parasites damage lung cells and tissues as they generally reside in the pulmonary arterial system of its host.

Cats with heartworm would show symptoms typical to a respiratory disease. Coughing, wheezing and breathing difficulties are common symptoms. Anorexia, lethargy, vomiting and progressive weight loss are the other clinical signs. Some infected cats would not show any symptoms but die suddenly. Heavy infestation is unusual in cats because of these animals resistance to heartworm. It is unusual for cat to have microfilaria in the blood stream and because of these animals’ resistance to this type of parasite, heavy infestation is very rare. However, because of the low tolerance, 2 or 3 of these 8 inch spaghetti-like worms can already kill a cat. Even up to this day, there is no safe and approved heartworm treatment for cats. Available treatments used in dogs can have fatal effects on cats. Cat’s arteries are very small. One adult worm that dies and deteriorates to pieces can cause a blockage in the arteries that will result to the death of the cat.

As there is no acceptable treatment, prevention will be the only way to save the pet from the fatal effects of these nasty parasites. Heartworm preventive products are now available in the market. It would be a wise idea to take the pet to a vet for the necessary heartworm testing and for the administration of the preventive products.