10 Things You Didn’t Know About Heartworm Disease

Most pet owners have heard a lot about heartworms from their veterinarian, friends, or commercials. Since we have seen a rise in heartworm disease in our area this summer, we would like to teach you 10 things that you didn’t know about heartworms.

1. Heartworms have long lasting effects even after the infection has been cleared. Dogs are the natural host for heartworms, which means that they live inside the dog, mature to adults, mate, and produce offspring. Dogs can carry several hundred worms in their heart, lungs, and arteries, which significantly impacts the dog’s health and quality of life even after the parasites are gone! Long lasting effects of heartworm disease is why it is so important to prevent heartworm disease rather than treat it after the infection has started.

2. Cats cannot undergo heartworm treatment like dogs, so prevention is the only means of protecting them from this potentially fatal disease. Cats cannot handle the heartworm treatment that is administered to dogs. Cat heartworm disease is very different than in dogs, because cats are an atypical host and most worms do not survive to the adult stage.

3. Cats typically just have 1 to 3 immature worms, which means that heartworm disease often goes undiagnosed in cats. Heartworms in cats can cause significant damage, even though there is a smaller worm burden. Our feline friends experience what is called heartworm associated respiratory disease (HARD). Cats also have very small hearts, which means even 1 to 3 worms can cause significant damage.

4. Clinical signs of heartworm disease in cats can be very subtle or very dramatic. Cats infected with heartworm disease may experience coughing, asthma-like attacks, periodic vomiting, lack of appetite, or weight loss. On more rare occasions cats may have difficulty walking, faint, have seizures, or develop fluid accumulation in the abdomen.

5. Infected mosquitoes carry teeny- tiny baby heartworms called microfilaria, which are transmitted to our pets when the mosquito takes a blood meal from them. Once the microfilaria is inside the host it takes approximately 6 months for the larvae to mature into adult heartworms.

6. Veterinary tests used to diagnose heartworms only detects the adult worms, which means it can be up to 6 months before you see a positive test. This is one reason why all dogs should be tested annually for heartworm disease.

7. Once heartworms are mature they can live for 5 to 7 years in dogs and up to 2 or 3 years in cats! Since heartworms can live for extended periods of time, each time our pets are bit by an infected mosquito this can lead to an increasing number of worms.

8. Dogs and cats aren’t the only species that can be infected by heartworms. Ferrets, sea lions, wolves, coyotes, foxes, and in rare instances, humans can also become infected with heart worms. Since wild life, such as foxes and coyotes, live close to urban areas they are considered important carriers of disease.

9. Heartworm disease is in all 50 states and most pets that are infected are mostly indoor pets! This is why prevention and annually testing for heartworm disease is so important.

10. Heartworm preventatives work by eliminating the immature (larval) stages of the heartworm parasite. This includes the infective larvae deposited by the mosquito as well as the following larval stages that develop inside our pets. Giving heartworm prevention late can allow immature larvae to become adults, which is poorly treated by monthly preventatives.

For more information about heartworm disease be sure to ask your veterinarian here at Dupont Veterinary Clinic or visit the American Heartworm Society’s website at www.heartwormsociety.org.  Also, for special offers on heartworm preventive, visit our homepage and click on “Special Offers”.

By Ashley Dawes, DVM