Heartworm disease is caused by a worm that is carried by mosquitoes. Inside the mosquito's body, the tiny worm is called a microfilaria. The microfilaria is injected into the pet's body when the mosquito bites and sucks blood. Your pet's blood transports the microfilaria to the heart and through the heart to the blood vessels in the lungs (pulmonary vessels). Protected within the heart and pulmonary vessels, the heartworm matures to adulthood and grows to be several inches long. As an adult, the heartworm is able to breed with other heartworms and produce microfilaria. These tiny microfilaria are picked up by blood-sucking mosquitoes and carried to other pets where they can be injected under the skin and migrate to the heart.
Heartworms are carried by mosquitoes
Heartworms can be fatal
Heartworms can be difficult to treat but are easy to prevent
Studies show 50% of cats infected with heartworm larvae have significant disease of the small arteries supplying blood to the lungs
Recommended Pet Medications for
Heartworms in Dogs and Cats
Which Pets Are Most at Risk for Heartworm Disease?
Heartworm disease has been diagnosed in all 50 states and is most concentrated in the eastern United States, the southern United States, and near Midwestern river valleys, including areas along the Mississippi and Ohio Rivers.
Pets that live outdoors are at the most risk for heartworm disease although in a North Carolina study, 28 percent of the cats diagnosed with heartworm were inside-only cats. This is because while outside pets are more susceptible to mosquitoes, mosquitoes can also get inside your home and deliver the one bite necessary to spread the disease.
• Pets living outdoors
• Pets living near standing water
• Pets living in southern/eastern US or along rivers
Max's Tip: Don't assume pets living indoors-only are not exposed to heartworm-carrying mosquitoes. It's wise to use heartworm preventatives to protect all your pets.
