Dog Heartworm Medicine Comparison Chart | Which One Fits Your Dog

A dog heartworm medicine comparison chart is the fastest way to see how products differ, because no single preventive covers everything. Your dog’s age, weight, local parasite risks, and tolerance for monthly tasks all shape the right pick. The chart below lays out the major options so you can match one to your situation without sifting through a dozen brand pages.

How the Top Heartworm Medicines Compare

All are monthly unless noted.

Other brands like Iverhart Max and Revolution use the same families of active ingredients, so the table covers the main decision points. For a closer look at how specific products perform in real-world use, see our hands-on roundup of top heartworm medicines.

What to Watch For When Choosing

Three factors narrow the field faster than brand comparisons: your dog’s age and weight, the parasites in your region, and the practical routine you can stick with.

Age and weight set hard limits. ProHeart 6 requires 6 months of age and Heartgard Plus, Interceptor Plus, and Sentinel Spectrum are safe from 6 weeks. Advantage Multi needs 7 weeks and a minimum of 3 pounds. Simparica Trio starts at 8 weeks. Checking the minimum before buying prevents wasted doses and avoids a trip back to the vet.

Parasite coverage determines whether you need a second product. Heartgard Plus covers only heartworm plus hookworms and roundworms. If your dog needs flea or tick protection, you would add a separate monthly product. Simparica Trio and Advantage Multi bundle flea control into the one dose. Interceptor Plus and Sentinel Spectrum add tapeworms. Dogs that roam wooded areas or interact with other animals benefit from broader coverage—fewer monthly products to track and fewer gaps in protection. The American Heartworm Society’s preventive chart is the best single reference for matching product spectrum to regional risk.

Oral, topical, or injection changes the routine. Chews are the most popular because they are simple to give, but some dogs refuse them or vomit after eating. Topicals bypass the stomach and work well for dogs that spit out chews, but they require correct application directly on the skin and no bathing for 24 hours afterward. ProHeart injections remove the monthly task completely—your vet gives a shot that protects for 6 or 12 months—but they cannot be reversed once administered, and your dog must be old enough. Talk the injection route over with your veterinarian to confirm it fits your dog’s health history and your comfort level.

Breeding and food sensitivities matter too. Heartgard Plus and Advantage Multi are both safe during breeding and lactation. Heartgard Plus uses a beef-based chew, so dogs with beef allergies may need an alternative like Interceptor Plus (tablet) or Sentinel Spectrum, which have no beef consideration. Always check the full label before starting a new preventive.

The American Heartworm Society stresses that every dog should test negative for heartworm before starting any preventive. Annual testing remains the standard of care even if you never miss a dose—no preventive is 100% effective, and early detection is critical.