What are heartworms?
Heartworms are parasites that live in an animal’s heart and adjoining blood vessels, where they interfere with normal blood flow. They are thin, white and between 6-14 inches long at maturity.

Where do heartworms come from?
Heartworms are transmitted from animal to animal only by mosquitoes. An infected animal can have thousands in microfilariae, or baby heartworms, in its blood. When a mosquito bites, the microfilariae infect the mosquito, where they grow for several weeks before being transferred to another animal. Once in the new animal’s blood, the microfilariae migrate through the body for several months until they enter the heart and mature into adults, where they begin reproducing and cause health problems. It takes 6-7 months from the time of the infected mosquito bite to the time the heartworms reproduce. At this point a mosquito bite will be able to transfer the infection to a new animal.

Can people and other pets become infected?
Dogs, cats and ferrets can become infected if bitten by in infected mosquito. Heartworm is not passed from animal to animal.
There have been some instances of heartworm infection in people, but this is rare.

Clinical signs and symptoms
Coughing, difficultly breathing, weight loss, and listlessness, fainting and even sudden death during exertion are symptoms of the disease. By the time heartworm disease causes symptoms, the disease is probably very advanced.

Diagnosis
A quick blood test can detect heartworm disease. Ideally, this test should be done on a yearly basis.
If your dog tests positive, more extensive blood work and x-rays will be done to determine the extent of the damage and evaluate for treatment.

Treatment for a heartworm positive dog
Treatment consists of several injections over a two day period, during which time your dog must be hospitalized and monitored for any side effects and also to restrict activity. These injections kill the adult heartworms. Another injection is given 4-5 weeks later.
Your pet must have restricted activity during this entire time to prevent the dying worms from clogging and damaging the small arteries in the lungs.

Prevention
There are several methods of preventing heartworm infections. One is a chewable tablet, called Heartgard, which is given monthly. This tablet also controls roundworms and hookworms. Another method is Proheart 6 injections, which is an injection given every 6 months. This also controls hookworms. A third option is Revolution, which is a monthly topical applied between the shoulder blades. Revolution also controls fleas and earmites.

We want to help you prevent your dog from getting heartworm disease through appropriate testing and preventative medication. Ask us for more information.