Heartworm prevention is non-negotiable for dogs in most of the US. The infection is serious, treatment runs $1,000–$3,000, and it can kill. Skipping prevention to save money isn't a real option. But overpaying for the same protection is.
What's in Heartgard Plus
Heartgard Plus is a monthly beef-flavored chewable with two active ingredients: ivermectin, which kills heartworm larvae before they can mature, and pyrantel pamoate, which controls roundworms and hookworms. It's been on the market for decades and is the most recognized name in the category — which is part of why it's priced the way it is. A 6-month supply for a medium dog typically runs $55–$80 depending on where you buy it.
The generics
The FDA has approved several generics that contain the same active ingredients at the same concentrations:
- Iverhart Plus — most widely available, same formulation as Heartgard
- Tri-Heart Plus — FDA-approved, often slightly cheaper than Iverhart
- Nuheart — tablet form rather than chewable
These typically cost 25–40% less than Heartgard for the same number of doses. The FDA requires bioequivalence for approval, meaning the generic delivers the same ingredient at the same absorption rate as the brand. It's not a lesser version.
The one real variable: palatability
Some dogs won't take a generic chewable as readily as Heartgard's beef-flavored formula. That's a legitimate consideration. If your dog reliably takes Heartgard and refuses the generic, the brand is worth the difference. If your dog takes both, there's no reason to pay more.
A note on herding breeds
Collies, Australian Shepherds, Shelties, and related breeds can carry the MDR1 mutation, which makes them sensitive to ivermectin at higher doses. The dose in heartworm preventatives is generally considered safe even for affected dogs, but mention it to your vet if you have a herding breed before switching anything.
Cost comparison
| Product | 6-month supply (medium dog) | |---|---| | Heartgard Plus | $55–$80 | | Iverhart Plus | $35–$50 | | Tri-Heart Plus | $30–$45 |
Prices shift by retailer and your dog's weight tier. Check PetSaver for current prices before you buy.
Most vets are fine prescribing generics when asked. At your next appointment: "Is there a generic heartworm preventative that would work for my dog?" is all you need to say.