Heartworms & Other Parasites

Why Dogs and Cats Need Heartworm Protection

pet owner holding dog

Heartworm disease is a disease caused by worms that damage various organs by speading through the bites of mosquitoes, which is a vital concern for every pet parent. Prevention is an important part of providing essential care, and heartworm disease prevention for pets is something every parent can provide. According to the American Heartworm Society, more than a million dogs have heartworm disease with cases found in each state1. Cats are also at risk for heartworm disease and are more likely to go undiagnosed since it is harder to detect in cats than dogs.

Read on to discover some common myths out there so you can be as smart as possible about protecting your pet from heartworm.

MYTH: Your Pet Does Not Need to be Screened Annually for Heartworm

Getting your pet checked for heartworm while they are at their annual veterinarian appointment is vital for their health and protection. It takes about six months for a heartworm infection to be recognized and detected even with routine testing, given the lifecycle of heartworms. By getting a heartworm test from the veterinarian on a regular basis, you can keep your pet healthy with early detection and treatment, potentially saving their life!

MYTH: Your Pet Does Not Need Heartworm Preventatives Outside of Mosquito Season

The American Heartworm Society recommends year-round preventions, since the mosquito species are constantly changing and adapting to colder climates, and have the ability to overwinter indoors2. Instead of second guessing when your pet is at highest risk, be safe and give your pet preventatives all year round.

MYTH: There's No Need to Stick to a Regular Schedule for Giving Heartworm Preventatives

As with other preventatives, it's important to be consistent when giving your pets their heartworm medicine. Whether they receive their preventatives by a monthly oral, a topical medication, or an injection directly from their veterinarian, keeping on schedule will ensure there are no gaps in protection.

MYTH: Heartworm Preventatives Protect Pets Solely from Heartworm Disease

Did you know that most preventatives protect your pets from other non-heartworm carrying parasites, as well? Some help protect pets from intestinal worms. Others can also help protect against fleas and certain ticks and mites. Be sure to talk to your veterinarian about which product offers the protection your pet needs.

MYTH: All Parasite Protection Products Protect Against Heartworm

With many products on the markets, it can sometimes be hard to decipher which parasite protection product is best for your pet. Many may think their flea and tick prevention product is protecting from heartworm as well when it is not. Be sure to check with your veterinarian to ensure your pet is receiving protection from heartworm, too.


Incorrect! Heartworm is a potentially fatal disease. If a pet show signs of heartworm (coughing, distended abdomen, weight loss, diffculty breathing, and excercise intolerance) your veterinarian will likely perform blood and serum tests to confirm the presence of heartworms. They may also use radiographs or an ultrasound to understand the extent of the disease. Once heartworms are confirmed, medication is administered to kill the heartworms and the pet will be hospitalized for 2-3 days to be kept inactive and closely monitored. Then, pets are usually confined to a small room or kennel with no exercise for up to 2 months to minimize risk of complications. After all that, diagnostic tests will be repeated to see if the heartworms have been cleared. Treating heartworm is a big deal, but prevention isn't! That's why your veterinarian recommends heartworm prevention.


  1. American Heartworm Society https://www.heartwormsociety.org/pet-owner-resources/heartworm-prevention-for-dogs
  2. American Heartworm Society https://www.heartwormsociety.org/pet-owner-resources/heartworm-basics#i-live-in-a-northern-state-how-long-should-my-dog-be-on-heartworm-prevention