Heartworm disease in dogs
Heartworm disease is caused by worms spread by mosquitoes that live in the heart and lung arteries. It's serious but very preventable.
Last updated: October 2026 · 3 sources · see sources
Signs to watch for
- Often no signs early
- Mild cough
- Tiring easily
- Weight loss
- Swollen belly in advanced cases
Trouble breathing, collapse, repeated vomiting, not peeing, or a seizure that lasts more than a few minutes needs a vet right away. See when to see a vet.
How vets diagnose it
A yearly blood antigen test finds most infections. Positive dogs get more tests, often chest X-rays, before treatment. [3]
How it's treated
Treatment usually involves a series of melarsomine injections, doxycycline and strict rest for weeks to months. Prevention is far cheaper. [3]
Medicines your vet may mention: Doxycycline, Ivermectin (Heartgard), ProHeart. We don't list doses; your vet will decide what fits your pet.
What it costs to diagnose and manage
| Item | Typical US price | Src |
|---|---|---|
| Diagnosis (exam and tests) | $35–$75 | [1] |
| Treatment | $1,000–$3,000 | [1] |
| Heartworm treatment (CareCredit) | $1,200 to $1,800 | [2] |
These are typical US ranges from the sources listed. Your pet's costs depend on how severe things are, the tests your vet recommends, your pet's size and where you live. Ask your vet for a written estimate.
Outlook
Most dogs recover with treatment, but it's hard on the body. Monthly prevention keeps it from happening again. [3]
Common questions
What is heartworm disease in dogs?
Heartworm disease is caused by worms spread by mosquitoes that live in the heart and lung arteries. It's serious but very preventable.
What are the signs of heartworm disease?
Common signs include: often no signs early, mild cough, tiring easily, weight loss, swollen belly in advanced cases.
How do vets diagnose heartworm disease?
A yearly blood antigen test finds most infections. Positive dogs get more tests, often chest X-rays, before treatment.
How is heartworm disease treated?
Treatment usually involves a series of melarsomine injections, doxycycline and strict rest for weeks to months. Prevention is far cheaper.
How much does heartworm disease cost to treat?
Diagnosis (exam and tests): $35–$75; Treatment: $1,000–$3,000; Heartworm treatment (CareCredit): $1,200 to $1,800. Costs vary with severity, tests, your pet's size and where you live.
Related
This page is general information for pet owners, not veterinary advice. Talk to your vet about your own pet.