Both dogs and cats can get heartworms (Dirofilaria immitis), which are parasitic roundworms. If your pets aren’t taking heartworm prevention, they could get the parasite from a mosquito that has been infected. Heartworm disease can be avoided if you follow your veterinarian’s recommendations for heartworms prevention.

Dogs are “natural” hosts for heartworms, which means that juvenile heartworm parasites can complete their life cycle once infected. Heartworms make their way into your dog’s heart, lungs, and blood vessels as they mature. They can grow up to a foot long once they get there. It’s conceivable for a single dog to have hundreds of heartworms.

Heartworms in dogs can cause major health problems and even death if not treated appropriately. This is why it’s critical to keep your dog on heartworm protection at all times. Nobody wants to learn that their dog has heartworm, but the good news is that the majority of affected dogs can be treated effectively. If your dog does develop heartworm disease, the process and treatments they will need to go through are outlined here.

If your dog tests positive, here’s what to expect:

Confirm that the diagnosis is correct

If a dog’s antigen test results are positive, the diagnosis should be confirmed with a second—and different—test. Because heartworm treatment is both costly and complicated, your veterinarian will want to be sure that it is essential.

Exercise should be limited

This condition may be tough to follow, particularly if your dog is used to being active. However, as soon as the diagnosis is established, your dog’s typical physical activity must be limited, as physical exertion speeds up the rate at which the heartworms cause damage to the heart and lungs. The less activity your dog has, the less the symptoms are.

Ensure that your dog’s illness is under control

Your dog’s condition may need to be stabilized with suitable therapy before true heartworm treatment can begin. The treatment can take several months in extreme cases of heartworm illness or when a dog has another significant ailment.

Treatment should be administered

When your veterinarian determines that your dog is stable and suitable for heartworm treatment, he or she will propose a multi-step treatment program. Treatment effectiveness is excellent in dogs with no or minor indications of heartworm illness, such as cough or exercise intolerance. Although the more severe diseases can be successfully treated, the risk of consequences is higher. Heartworm disease severity does not usually correlate with the degree of symptoms, and dogs with numerous worms may have little or no symptoms early on in the disease’s course.

Treatment, test, and prevention for care

Your veterinarian will do a heartworm test 6 months after treatment is completed to ensure that all heartworms have been eradicated. To ensure that your dog does not get heartworm disease again, you should give him heartworm prevention year-round for the rest of his life.

What can I do to keep my dog from contracting heartworms?

A heartworm preventative can help your dog avoid contracting heartworms. After a dog has been successfully treated for heartworms, it is vital to start a heartworm prevention program to avoid recurrence. There are many safe and affordable heartworm preventives available today that prevent pets from suffering deadly diseases. Determine which heartworm prevention program is best for your dog by consulting with your veterinarian.

Here are some of the popular options your vet may suggest you for your dog’s heartworm prevention/treatment:


Advantage Multi is a topical treatment that protects your pet against a variety of parasites in addition to heartworms. It contains the active ingredients imidacloprid and moxidectin, which protect against fleas, sarcoptic mange mites, hookworms, whipworms, and roundworms.


One of the most popular heartworm preventatives on the market is Heartgard Plus. It protects dogs from heartworms and treats and controls hookworm and roundworm infestations with ivermectin and pyrantel. It’s simple to administer, and compared to topical treatments, Heartgard Plus is a very cost-effective choice. It’s safe for pets over 6 weeks old and weighs at least 3 pounds.


Sentinel employs milbemycin oxime and lufenuron to protect dogs from heartworms, hookworms, whipworms, and roundworms in dogs aged 4 weeks and up and weighing 2 pounds or more. It also disrupts the flea life cycle by preventing flea eggs from maturing. Though it costs more than Heartgard Plus, when you consider the extra parasite protection it provides, it’s still a good deal.


Interceptor is a popular beef-flavored monthly preventive alternative to the more well-known Heartgard anti-heartworm drug. It contains the active ingredient Milbemycin Oxime, an antihelminthic as a major component. This means that it can protect your pet against hookworms, whipworms, and roundworms in addition to heartworms.


Revolution’s active ingredient, selamectin, protects against fleas, sarcoptic mange mites, ear mites, and some ticks (including the American dog tick), as well as heartworms. It’s safe for canines over the age of six weeks.

Bottom Line

Some heartworm preventives just protect pets from heartworms, while others protect pets from heartworms and intestinal parasites, as well as heartworms, intestinal worms, fleas, ticks, and mites. Because doctors are familiar with the parasites that are prevalent in the area where they practice, pet parents should consult with their veterinarian about which treatment or products will be most effective for their pets.

It is advised that all dogs be tested for heartworm prevention on an annual basis. Consult your dog’s veterinarian to determine the ideal time for an annual heartworm test.