Heartworm medication is available only on prescription. Because this disease is hazardous, administering the wrong medicine can harm the dog. Therefore, for effective heartworm prevention, it is essential to consult a veterinarian and obtain a prescription.
In the U.S and many other countries, no over-the-counter heartworm preventive exists. But some stores and online sellers advertise “dewormers” like pyrantel pamoate and febendazole as OTC, but these are used to treat only intestinal worms like roundworms, hookworms, whipworms, and tapeworms. These medications do not protect against heartworms.
Chart Showing Over-the-Counter and Prescription Separately
Here a simple table showing non-prescription and prescription medication separately:
Medicine |
Need a Prescription? |
What is it for? |
|---|---|---|
Ivermectin (Heartgard, Iverhart) |
✅ Yes |
Heartworm prevention + some intestinal worms |
Milbemycin Oxime (Interceptor, |
✅ Yes |
Heartworm prevention + intestinal worms |
Moxidectin (Advantage Multi, ProHeart injection) |
✅ Yes |
Heartworm prevention + flea & some worms |
Selamectin (Revolution |
✅ Yes |
Heartworm prevention + fleas, mites & some worms |
Pyrantel Pamoate |
❌ No |
Only stomach worms (Roundworm, Hookworm) |
Fenbendazole |
❌ No |
Roundworm, Hookworm, Whipworm + some tapeworm |
Praziquantel |
❌ No |
For Tapeworm Only |
FAQs
Can I give my dog over the counter heartworm medicine?
There is no over the counter heartworm prevention if your dog has an active infection. You need a prescription from your veterinarian. Giving prevention on your own can be deadly.
Can I get heartworm medication without a vet?
Heartworm medication is available only on prescription from your veterinarian. Because it is important to make sure your pet has tested negative for heartworms.
Can you treat your dog yourself for heartworms?
You should not treat your dog yourself for heartworms. Please take your dog to the veterinarian as soon as possible. Your veterinarian will determine a treatment schedule based on the severity of the infection.
Do You Need a Prescription for Preventive Medication To Avoid Heartworms?
Yes, you definitely need a prescription to kill immature heartworm larvae.
Is OTC heartworm medicine for dogs available on Walmart and Amazon?
You cannot buy FDA-approved over the counter heartworm medicine on Walmart and Amazon. Although some products on Amazon and Walmart claim to be heartworm medicine, they are for other types of worms (such as roundworms or hookworms) and do not protect against heartworm disease, which is serious and potentially fatal.
What is the best over-the-counter heartworm prevention for dogs?
Heartworm preventives are not available OTC. They are prescription only.