Heartworm Disease in Dogs and Cats

Keeping Your Pets Safe

Heartworm disease is a preventable, but potentially fatal disease caused by parasitic worms. Heartworm infections are most commonly associated with dogs, but they can infect cats, ferrets, and other wild animals. Heartworm disease is transmitted through mosquitos that deposit larvae. These grow inside the circulatory system of animal and reside in the heart, lungs, and associated blood vessels.

The parasite is spread through mosquito bites. Infected mosquitos carry the larvae, or young worms, which then enter the blood stream of the animal after a bite. The parasite grows over the next 6 months, up to a foot long, and eventually make their way to the heart and lungs. Here, they reproduce and make offspring. The baby worms, called microfilariae, travel through the bloodstream. When a mosquito bites an infected animal, the baby worms enter the mosquito, and the cycle is repeated and spread to other
animals.

Dogs are the natural host for heartworm parasites, which means the worms can grow into adults and reproduce offspring. Dogs can harbor hundreds of heartworms in their system causing heart failure, lung disease, and damage to other organs in the body. Signs of heartworm disease include coughing, difficulty exercising, decreased appetite, weight loss, and lethargy. As the disease progresses dogs can develop swollen bellies due to fluid build-up, heart failure, and collapse from blocked blood flow.

Heartworm disease in cats is much different. Cats are not the natural host, and therefore the worms cannot grow into the adult phase. While cats do not harbor as many worms, even immature worms can cause damage and cause heart disease. Cats show signs of coughing, vomiting, lack of appetite and weight loss, difficulty moving, or collapse and sudden death. There is no current treatment for heartworm infections in cats, so it is critical to keep them on heartworm prevention.

A common belief is that heartworm does not exist in Colorado, but this is not true. Heartworm has been
diagnosed and is prevalent in all 50 states. Heartworm disease, even if treated, can have lasting effects. Treatment is 15x more expensive than a year’s worth of preventative! Additionally, treatment is hard for the animal, making prevention the best option, every time. Keep your pets safe and reduce the incidence of disease spread by keeping your pet on heartworm prevention.