5 Common Misconceptions About Heartworm Disease

Share on facebook
Share on twitter
Share on linkedin

April is Heartworm Awareness Month.

We asked Dr. Kristen Smith, a veterinarian on the Petzey network, to share her expertise about the disease.

From general health questions to urgent concerns, use the Petzey app to talk or video chat with a licensed vet professional to get answers in minutes. If a trip to the vet clinic or hospital is needed, we’ll help find ones near you.

As a veterinarian, I consider education regarding heartworm disease prevention to be one of my most important responsibilities.

This horrible disease is transmitted to our pets through mosquito bites and eventually leads to the infestation of the heart with parasitic worms. These worms clog arteries and cause extreme physical damage to the heart and lungs which, left untreated, can cause death.

Fortunately, readily available FDA-approved heartworm preventatives are extremely effective in protecting animals from contracting this disease when dosage instructions are accurately followed.

While heartworm disease varies depending on geographical location, the disease is present in all 50 states. Dogs are not the only species susceptible to heartworm disease, and it is generally recommended that cats and ferrets also receive preventative medication. The American Heartworm Society recommends that pet parents provide their pets with heartworm prevention all 12 months of the year. Mosquitos are becoming more resistant to cold temperatures (I can personally attest to the presence of a mosquito in my Michigan household back in January).

Many misconceptions exist with regard to heartworm disease. Below are some of the more common clarifications to improve our understanding of the disease:

1. Heartworms cannot be detected on a fecal examination. Testing for heartworm disease is done on blood samples. If your dog has not had blood drawn in the last 12 months, then he/she has not had a heartworm test in the last year.

2. Indoor dogs and cats are still susceptible to heartworm disease even if they have minimal exposure to mosquitos.

3. Heartworm disease is transmitted through mosquito bites and not from direct contact between animals. An infected dog cannot transmit the disease to another dog except through the bite of a common mosquito.

4. Dogs frequently do not show signs of illness until late in the course of the disease. For this reason, it is unwise to assume that a dog is not infected based only on a healthy appearance.

5. While treatments are available for dogs who have contracted heartworm disease, the expression “an ounce of prevention is worth a pound of cure” describes this disease perfectly. Not all dogs with heartworm disease are good candidates for treatment, and the treatment itself is costly, prolonged, and requires lengthy restrictions on a dog’s activity.

I highly recommend pet parents familiarize themselves with the anti-parasite drugs they give their pets. Many who are giving their pets monthly flea and tick preventative mistakenly thought those products also provided protection from heartworm disease when, in fact, they did not.

Likewise, many products that are safe for dogs are not safe for cats or other species. Be sure to check the labels of any medications for safety information and to ensure that your pet is on a product that helps protect against heartworm disease.

Understanding heartworm disease can be confusing due to the complicated life cycle of this parasite. For this reason, the American Heartworm Society provides a wealth of information for pet parents on their website

Got questions about heartworm disease? Use Petzey to talk or video chat with a licensed vet professional to get answers right away, all for only $20 a consultation.

This information is offered for informational and educational purposes only, and is not intended to replace traditional veterinary medical advice or create a veterinarian-client-patient relationship. You should not change your pet’s care or treatment on the basis of this information. If you think your pet requires emergency assistance, you should take your pet to the nearest emergency veterinary hospital.