A Dog Owner’s Guide to Heartworm Treatment

If your dog has been diagnosed with heartworm disease, you may wonder what treatment involves, how much it will cost and how heartworm could impact your dog’s quality of life. A positive heartworm test can be scary, but knowing what to expect can help you feel confident during the treatment process.

Here is an overview of what heartworm treatment typically involves and how much it will cost.

How Does Heartworm Treatment Work?

Treating heartworm in dogs can be more involved than treating most other worms. There is no pill or quick fix — the process requires multiple veterinary visits, medications and close monitoring over several months.

Preparation and pre-treatment

Before starting treatment, your veterinarian will run tests to confirm the diagnosis, check for heart or lung damage caused by the worms and ensure your dog is healthy enough to undergo treatment. Tests may include:

• Blood tests to look for evidence of adult worms and circulating larvae
• Complete blood panel to check overall health and organ function
• X-rays or ultrasounds to check for heart and lung damage

Before treatment, your veterinarian may prescribe a course of oral antibiotics that target Wolbachia bacteria that live inside the heartworms. This step helps make the worms easier to kill and helps to reduce inflammation that can occur in the body as the worms die.

Your vet may also start your dog on a heartworm medication to prevent them from acquiring new worms, and a steroid to further reduce the chance of inflammation. Beginning in this phase and continuing throughout treatment, your dog’s activity level will be restricted, as exercise can increase the possibility of complications.

Melarsomine injection regimen

After one to two months of pre-treatment, your dog will receive treatment to kill the adult worms. This requires injections of a medication called melarsomine, spaced one month apart.

Most dogs follow a three-dose regimen of one injection, followed by a 30-day rest period and then two more injections spaced 24 hours apart. The shots are given deep into the back muscles and typically cause some pain and swelling. Most veterinarians recommend that dogs stay in the hospital for the day to monitor their response to each injection.

As the worms die, they can break apart and travel through the bloodstream, potentially leading to lung or heart complications. Keeping your dog calm and closely following all medication instructions from your veterinary team can greatly reduce the likelihood of this complication.

How Much Does Heartworm Treatment Cost?

The average cost* of heartworm treatment for a medium-sized dog ranges from $1,200 to $1,800.¹ However, heartworm treatment costs vary based on the severity of your dog’s infection, their health history, the treatment protocol your veterinarian prescribes and your geographic location.

Diagnosis and prevention costs

The national average cost* of a heartworm test for a dog is $71, but can range from $56 to $128.² The average cost* of a monthly dose of heartworm prevention is $14, but the cost can range from $11 to $25.²

Reduced-cost heartworm treatments

Humane societies and other nonprofit pet health organizations may offer reduced-cost heartworm treatment, especially when a newly adopted dog tests positive. Low-cost protocols may not follow the recommendations set by the American Heartworm Society, but they may be more financially feasible for some families. Low-cost heartworm treatment may range from $225 to $614.³

Average cost to treat heartworm in dogs by state/district

The following table shows the average cost of heartworm testing in each of the 50 states and the District of Columbia:²

Does Pet Insurance Cover Heartworm Treatments?

Heartworm treatment may or may not be covered by pet insurance policies. Since heartworm disease is preventable, some companies might deny treatment if you can’t prove that you consistently gave your dog an appropriate preventive medication. If you recently adopted a dog who tested positive, the company may cover treatment only if the policy was in place before diagnosis.

Every policy is different, and it’s worth checking your documents or speaking with a representative to determine coverage in the event your dog is diagnosed with heartworm infection. To ensure maximum coverage, you should administer preventive medication to your dog year-round.

Potential Complications of Heartworm Treatment

Heartworm treatment is generally safe when performed under a veterinarian’s supervision. Although treatment carries some serious potential complications, the possibility of heart damage and potential death is much higher if heartworm infection goes unchecked.

Possible side effects can arise from pre-treatment medications or the treatment itself. They include:

• Fever
• Injection site pain or swelling
• Lethargy
• Loss of appetite
• Mild cough
• Nausea or vomiting

These effects are usually temporary and can often be managed with supportive care from your vet.

The most serious complication of heartworm treatment comes from the worms dying off and breaking down in the bloodstream. Inflammation and the worms themselves can cause blockages in the heart or lungs, which, in the most severe cases, can lead to death. Strict activity restriction helps to reduce the potential for this.

During treatment, monitor your dog for signs of a serious reaction, including:

• Collapse
• Difficulty breathing
• Severe coughing

Recovery Tips Following Treatment

The key to a smooth recovery after dog heartworm treatment is following your veterinarian’s instructions carefully. Strict rest, good nutrition and adherence to follow-up visit and testing protocols are critical aspects of the process.

Activity restriction

The most important part of recovery is limiting your dog’s physical activity to reduce the potential for complications as the dead worms are absorbed by the body. Activity restriction includes cage rest and short leash walks for bathroom breaks. The restriction period begins as soon as pre-treatment starts and continues for about a month after the last injection.

Restricting activity for several months can be challenging and stressful for many dog owners. Your veterinarian may prescribe sedative medications to help keep your dog calm as they get used to the new routine. Puzzle toys, long-lasting chews and interactive training sessions can help keep your dog’s brain occupied while they rest.

Preventing Future Heartworm Infection

Once your dog has recovered from a heartworm infection, you must continue providing regular heartworm prevention. Chewable, topical and injectable formulations are available that work to kill immature heartworms — transmitted by mosquitoes — before they can mature into adult worms.

Heartworm infection causes damage to the heart and lungs, and future infections could compound this damage. Prevention is the best and most cost-effective strategy to keep your dog’s heart healthy and worm-free.

Understand Heartworm Prevention to Protect Your Pup

Heartworm treatment can be stressful and costly, but with early detection and proper veterinary care, most dogs recover well. Understanding how much dog heartworm treatment costs and what’s involved in the process can help you make informed decisions and prepare for what’s ahead. A routine, year-round prevention regimen can help you avoid heartworm treatment by protecting your dog from heartworm disease.

Frequently Asked Questions About Heartworm Treatment

Do you still have questions about heartworm treatment and associated costs in dogs? Here are answers to commonly asked questions by pet owners on this topic.

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The CareCredit credit card provides a convenient way to pay for your dog’s vaccinations and other health and wellness expenses, including exams, medications and products at providers in the CareCredit network.** Continue your wellness journey by downloading the CareCredit Mobile App. You can find a provider on the go, manage your CareCredit account and easily access the Well U blog for more great articles, podcasts and videos. Use our Acceptance Locator to find a veterinarian that accepts CareCredit to help keep your pet healthy and happy for a lifetime of love.

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Author Bio

Angela Beal, D.V.M., has more than 20 years of experience as a veterinarian. Leveraging her background in private practice and academia, she uses her passion for writing to convey information to pet owners to help them keep their pets healthy and happy.