Most pet owners know heartworm disease is a serious issue for their furry friends, but a lot of myths and misconceptions still circulate about this parasitic condition. See where you rank in your heartworm disease knowledge by participating in our guessing game. Choose whether each of the following statements is fact or fiction regarding this deadly disease. 

Fact or fiction: Heartworm disease is only common in warmer states that have a higher mosquito population.

Fiction: While it’s true that more cases occur in warmer areas, heartworm disease can affect pets nationwide, and has, in fact, been diagnosed in dogs in each of the 50 states. Arizona’s dry climate is not as ideal as Mississippi, or other warm, wet states, but we experience our fair share of heartworm disease cases. Regardless of the odds, the risk is always too high if your dog is the one infected with heartworms. 

Fact or fiction: If my pet is bitten by an infected mosquito, I’ll know if she gets heartworms by the way she acts.

Fiction: Heartworm disease can be a silent, deadly disease for months, and sometimes years, before your pet shows signs. Ironically, the more fit and active a pet, the quicker you’ll notice the common signs of exercise intolerance and coughing. During the six months that the immature heartworm larvae take to develop into adults, they are creating irreversible damage in your pet’s circulatory system, as they make their way to the heart and lungs. If your pet’s worm burden is low, you may not notice an issue for an extended time period, despite how quickly heartworm larvae begin attacking your pet. 

Fact or fiction: I’ll see heartworms in my pet’s stool like other worms.

Fiction: Heartworms are not intestinal parasites like roundworms, whipworms, or hookworms. Instead, they live inside your pet’s circulatory system, focusing on the blood vessels surrounding the heart and lungs. Intestinal parasites are passed in your pet’s stool, and you may see roundworms, but you will not see heartworms, which are not shed through defecation.

Fact or fiction: Heartworm treatment is hard on my dog.

Fact: Treating heartworm disease is much harsher on your dog’s body than routine prevention. Heartworm preventives kill off the immature heartworm stages, while heartworm treatment must be strong enough to kill the adult heartworms. To do this, an arsenic compound is injected deep in your dog’s lumbar muscles, with some heartworm-disease stages requiring up to three injections. During treatment, your dog must undergo strict exercise restriction for several months, to reduce the risk of potential side effects. Although giving your dog a pill each month may seem challenging, heartworm treatment is a much greater struggle.

Fact or fiction: If my cat gets heartworm disease, she can be treated like my dog.

Fiction: Sadly, no heartworm treatment labeled for cats is available, and only supportive nursing care can be provided to manage illness until the heartworms die. Fortunately, a variety of feline heartworm preventives are available that can ensure your cat does not have to suffer until these parasites die off. 

Fact or fiction: Indoor-only pets are at risk for heartworm disease, too.

Fact: You may think your home is an impervious bubble through which no bugs or insects can enter, but that is not the case when it comes to mosquitoes. These opportunistic pests seek the warmth of your home during the winter, and can sneak in through the tiniest hole in your window screen, or an open door, to infect your pet with heartworms.

Fact or fiction: My pet doesn’t need an annual heartworm test if she’s on year-round prevention.

Fiction: Annual heartworm tests may seem unnecessary if your pet is on year-round prevention, but they provide a variety of benefits.

  • Annual testing ensures your pet’s heartworm prevention is working correctly.
  • A yearly negative test ensures your pet receives each dose, and does not throw it up, or spit it out.
  • An annual negative test, paired with proof of year-round prevention, grants coverage of treatment costs by the manufacturing company if your pet develops heartworm disease.

Fact or fiction: A negative heartworm test is not always accurate.

Fact: Heartworm testing is tricky. The common heartworm test we perform at Palisades Veterinary Hospital is highly specific, so false negatives can occur. For a positive heartworm test, your pet must be infected with adult heartworms that are at least 6 months old, and enough adult female heartworms for the body to produce an antigenic response. For example, if your pet has adult heartworms, but they are all male, she will test negative. Or, if your pet was bitten three months ago by an infected mosquito, she will test negative at this time. This is another reason annual heartworm tests are an important part of your pet’s overall wellness plan.

Fact or fiction: Heartworm prevention is necessary during the winter months.

Fact: We live in Arizona—enough said. But, on a serious note, mosquitoes can emerge and seek out a victim when the temperature rises above freezing. If you travel somewhere frigid for the winter, your pet will still need heartworm prevention, because it takes only one day of warmer temperatures, or one in-home mosquito, to take advantage of your pet. 

Fact or fiction: My pet won’t take a pill, so there’s no heartworm prevention option for her.

Fiction: We understand giving pets pills can be difficult. Fortunately, we carry a wide variety of heartworm preventives, oral and topical, to ensure your pet will allow administration of at least one product. 

After learning how serious heartworm disease is in your pet, give us a call to discuss the best heartworm prevention options for your furry pal.