10 Common Myths About Heartworm Disease

By Nina Silbertsein
Like many diseases and health conditions, heartworm disease carries with it abundant myths. These myths can be a barrier to quality pet care as clients may not be equipped with accurate information.
The following table can help you as a practitioner replace myths with facts when educating your clients and training your hospital team on heartworm disease.

Myth #1: Indoor pets don’t need heartworm protection. 

Fact:  It’s impossible to keep your pets completely away from mosquitoes—even if they are indoor pets. Mosquitoes can get inside your home, and it only takes the bite of one to transmit heartworms.1

Myth #2: Pets only need “seasonal” protection from heartworms.

Fact: Although the risk of heartworm exposure is more common during the warmer months, it is a year-round risk that requires a year-round preventive.2

Myth #3: Heartworm disease doesn’t exist in every U.S. state.

Fact: Heartworm has been diagnosed in all 50 states. It is also extremely prevalent in the pet population of Puerto Rico, whose shelter pets are often sent to the United States for adoption.3

Myth #4: Dogs with heartworm disease should be separated from other pets to prevent the disease from spreading.

Fact: Heartworm disease can only be transmitted through the bite of a mosquito.4

Myth #5: Puppies are too young to get heartworms, therefore they don’t need a preventive.

Fact: Because any dog of any age can become infected with heartworms, it is recommended that dogs begin preventive treatment at 6 to 8 weeks of age.5

Myth #6: Only dogs get heartworms.

Fact: Heartworm disease does occur more frequently in dogs, but cats, ferrets and other mammals can be infected.6

Myth #7: Cats and dogs are affected by heartworm disease in the same way.

Fact: Signs in dogs include a cough, lethargy, difficulty breathing and, sometimes, spitting up blood. Many cats have no clinical signs; however, infected cats may exhibit signs of acute respiratory distress or may die suddenly.7

Myth #8: If a pet’s vaccines are current, heartworm won’t be an issue.

Fact: There is no vaccine against heartworm disease for dogs or cats.8 Heartworms can easily be stopped with simple, affordable, year-round preventive care, and there are several types of products to choose from, including a twice-a-year injectable for dogs, monthly topical application, and monthly tablets and chewables.

Myth #9: Treatment for heartworm disease is easy.

Fact: It is important to realize that the treatment for heartworm disease is neither simple nor risk-free. By the time the heartworms are detected, it is possible that severe damage to the heart, vessels and lungs may have occurred. There is no FDA-approved heartworm treatment for cats.9

Myth #10: People can get heartworms from their dogs.

Fact: Heartworm disease rarely affects people. It is transmitted to humans by mosquitoes and not directly by the dog.4

  1. The best insurance against heartworm disease. Banfield Pet Hospital. 2015. www.banfield.com/pet-health-resources/preventive-care/parasites/heartworm/insurance-against-heartworm-disease. Accessed August 21, 2015.
  2. Heartworm disease: Prevalence and year-round protection. Banfield Pet Hospital. 2015. www.banfield.com/pet-health-resources/preventive-care/parasites/heartworm/heartworm-disease-prevalence-and-year-round-preve. Accessed Aug. 21, 2105.
  3. Preventing heartworm disease in pets. Banfield Pet Hospital. 2015. www.banfield.com/pet-health-resources/preventive-care/parasites/heartworm/preventing-heartworm-disease. Accessed Aug. 21, 2015.
  4. Keep the worms out of your pet’s heart! The facts about heartworm disease. U.S. Food and Drug Administration. Animal & Veterinary. 2014. www.fda.gov/AnimalVeterinary/ResourcesforYou/AnimalHealthLiteracy/ucm188470.htm.
  5. Heartworm disease in dogs. The Merck Manual Pet Health Edition. 2011. www.merckvetmanual.com/pethealth/dog_disorders_and_diseases/heart_and_blood_vessel_disorders_of_dogs/heartworm_disease_in_dogs.html.
  6. Heartworm disease: It’s worse than you think. Banfield Pet Hospital. 2015. www.banfield.com/preventive-care/banfield-prevention/parasites/heartworm. Accessed Aug. 21, 2015.
  7. Shearer P. Literature review – heartworm disease. Banfield Applied Research and Knowledge. May 2011. www.banfield.com/getmedia/e456eec3-77f2-46f1-b302-87a17a8fba0a/5906a327-4e82-49f7-9432-e7da7fc568a9-pdf0. Accessed Aug. 21, 2015.
  8. Heartworm basics. American Heartworm Society. 2015. www.heartwormsociety.org/pet-owner-resources/heartworm-basics. Accessed Aug. 21, 2015.
  9. Client handout: Canine heartworm treatment. Banfield Pet Hospital. 2015. www.banfield.com/Banfield/media/PDF/Downloads/Canine-Heartworm-Treatment.pdf. Accessed Aug. 21, 2015.
Nina Silberstein graduated from the State University of New York College at Buffalo with a BA in journalism. She joined Banfield in 2008 as a medical writer/editor on the Marketing team. She and her husband, David, have one son, Graeme, and a black cat named Blackie.