Updated September 25, 2026. Fact-checked against veterinary sources; review by a licensed veterinarian is in progress. See our editorial policy.
Quick answer: Simparica Trio is a monthly prescription chewable for dogs containing sarolaner, moxidectin, and pyrantel. It’s labeled to prevent heartworm disease, kill fleas and certain ticks, and treat roundworms and hookworms. A negative heartworm test is needed before starting any heartworm preventive. Alternatives include other combination chews and separate heartworm and flea/tick products.
What it covers
- Heartworm prevention
- Fleas
- Several tick species
- Roundworms and hookworms
It doesn’t cover whipworms or tapeworms. Your vet can add coverage if needed.
Safety considerations
- Prescription only, with a heartworm test first
- Sarolaner is an isoxazoline. The FDA has noted this class can be associated with neurological reactions such as tremors, unsteadiness, or seizures. Tell your vet if your dog has a seizure history
- Possible side effects include vomiting and diarrhea
- Store chews out of reach. They’re flavored, and dogs may eat several
Alternatives
- Other combination chews that include heartworm, flea, and tick protection
- A heartworm preventive plus a separate flea and tick product
- Products that also cover whipworms, if they’re a concern in your area
Choosing
Your vet will consider your region’s parasites, your dog’s health and seizure history, and whether you prefer chews or topicals.
Sources
- Zoetis: Simparica Trio (sarolaner, moxidectin, and pyrantel chewable tablets) product label
- US FDA: Fact sheet for pet owners and veterinarians about potential adverse events associated with isoxazoline flea and tick products
- American Heartworm Society: Canine heartworm guidelines
- Companion Animal Parasite Council (CAPC): Canine guidelines
This article is for general education and is not a substitute for care from your own veterinarian. Learn about The Pet Vet and our editorial policy.