Monthly Medication Can Prevent Heartworm Disease

I hope you're not eating breakfast.

It was 20 years ago when I first saw "the jar" on a desk in the humane education room at the SPCA Tampa Bay in Largo. It was filled with formaldehyde - and a large canine heart oozing spaghettilike worms, some of them up to a foot long!

Obviously, they had killed the first owner of that heart.

Every dog I've had since has been on monthly heartworm preventative medication.

Heartworm disease is transmitted by mosquitoes, and we have plenty. We'll get even more when the rainy season starts in June.

"Heartworm disease is very serious," says veterinarian Jim Lutz of Largo Veterinary Hospital. "We typically treat one case a month, but animal shelters see a lot more of it with pets that are kept outdoors and not on heartworm preventative."

The disease is highly prevalent in dogs, less so in cats, in coastal regions of the Southeast.

Heartworm Central

As coastal Floridians, our pets live in the heartworm capital of the United States. While cases have been found in all 50 states, the highest infection rates are observed within 150 miles of the Atlantic and Gulf coasts and along the Mississippi River, according to the American Heartworm Society.

Heartworms are parasites approximately the diameter of thin spaghetti. In an infected dog or cat, they normally live free-floating in the right ventricle of the heart and nearby blood vessels. After your dog or cat is bitten by the carrier mosquito, the parasite matures into a worm over the next six to seven months.

Some have been known to grow up to 14 inches long.

The infestation can cause irreversible damage to the pulmonary arteries. Multiple mature worms can form a twisted, intertwined mass in the heart that blocks the flow of blood. The smaller the host, the fewer worms it takes to cause a problem. Ultimately, heartworm disease can lead to heart failure and death.

Although this parasite prefers a canine host, it can and does flourish in other animals.

"It can take between six and 12 months before we start seeing signs of the disease," Lutz says. "Once they set in, symptoms can include coughing, lethargy, loss of stamina and exercise intolerance."

Pets suspected of heartworm disease require a thorough evaluation at the vet's office, including chest X-rays and routine blood chemistry. The most common test to detect the disease is the heartworm antigen test.

Treatment can take up to four months and may include hospitalization, strict limitation of activity and prescription medications. Costs for treatment can start at $500.

Prevention Is Key

"People tend to think that since their pet stays indoors most of the time that they are not at risk for heartworm disease," Lutz says.

But it takes only one bite by a carrier mosquito to set in motion the heartworm life cycle. And it's all so easily avoidable with a monthly preventative medication.

Heartworm prevention is available in oral and topical versions and should be obtained from your veterinarian. Because of the prevalence of heartworm disease in our region, most veterinary exams include a heartworm test. Be sure to ask whether your vet plans to test as part of the general exam. Pets should always be tested before being started on a preventative medication.

Year-round prevention is recommended by most veterinarians in our region. For additional information about the disease, go to the American Heartworm Society's Web site, www.heartwormsociety.org.

And next time you're in Largo, stop by the SPCA Tampa Bay and ask to see "the jar."