Heartworm Disease is Everywhere

by Jennifer Mars, DVM, Carolina Veterinary

January 28, 2011

Heartworm disease is everywhere. The potentially deadly disease of dogs, cats and ferrets is totally preventable. Yet, according to one recent Gallup poll, only 59 percent of pet owners offer a potentially life saving preventative to their pets. Among the 12,000 veterinary clinics polled, more than 250,000 cases of heartworm disease were reported. And yet as I sit at the dog park weekly, disguised as a secretary or lawyer (no one asks them questions about their job!), I hear talk about the "scams" that veterinarians are pulling, trying to get pet owners to buy products to prevent this disease. Crazy!

Heartworms are spread by the bite of mosquitoes. The more mosquitoes, the greater incidence of this disease. Five states consistently with the highest incidence in the US are Texas, Florida, Louisiana, Georgia, and, of course, North Carolina. All 50 states had incidents of heartworm disease. Every year in North Carolina alone about 20,000 cases of heartworm disease are reported. Many of these are rescues or strays that have not had proper medical care. However, many are pets who have loving owners who are either unaware of the problem or who have gotten caught up with busy daily life and forgotten to give the medication that was bought with such good intentions.

Heartworm (scientifically known as Dirofilaria immitis) is a fairly large worm, up to 14 inches long, that in adulthood lives in the heart and pulmonary arteries of an infected dog. The worm's presence generates a strong inflammatory response and a tendency for blood to inappropriately clot. If enough worms are present, the heart must work extra hard to pump blood through the plugged up arteries. Side effects of heartworms include heart disease, kidney disease, lung disease, heart failure and even death.

Heartworm disease is easily avoided by a once-a-month tablet or topical application aimed at killing all of the baby heartworms within your dog's body. Most preventative medications also serve as a monthly dewormer. Before starting heartworm prevention, your dog should be tested for heartworms as the preventative medications can be dangerous to a positive dog. For that reason, we recommend routinely testing your dog, usually once every one to two years, even when on prevention. Veterinarians recommend starting puppies as young as 6 weeks old on a regimen. Forgetful pet owners should register at remindmypet.com for monthly text or email reminders.

And, yes, our furry feline friends can also develop heartworm disease. As little as one heartworm can cause significant heart disease and death. Please talk to your veterinarian about options for your outdoor cat.

For about a quarter a day, you can save your pet's life (monthly, that's about two lattes or lunch at Panera). More information about heartworm disease can be found at www.heartwormsociety.org.