Neither Heartgard nor Simparica Trio is inherently "safer"; they serve different primary purposes and have different safety profiles for specific dogs, with Heartgard often preferred for young puppies, pregnant/breeding dogs, or those only needing heartworm/worm prevention, while Simparica Trio offers broader, all-in-one protection (fleas, ticks, worms, heartworm) but isn't safe for breeding/pregnant dogs, making the best choice dependent on your dog's age, lifestyle, and health needs, as determined by your vet.
Simparica is safe for use in dogs ages 6 months and up, and Heartgard Plus can be administered to puppies from the age of 6 weeks. Heartgard Plus is also safe for use in breeding or pregnant female dogs, while Simparica has not been evaluated for safe use in breeding, pregnant, or lactating dogs.
Simparica Trio™ has not been evaluated in dogs that are pregnant, breeding or lactating. Simparica Trio™ has been safely used in dogs treated with commonly prescribed vaccines, parasiticides and other medications. Use with caution in dogs with a history of seizures.
There are several oral prescription flea and tick medications that are safe for dogs. These preventatives come in pill and chew forms. Your vet can help you find the right one for your pup's age. Credelio Quattro is an excellent choice for flea and tick protection.
Monthly Simparica Trio prevents heartworm disease, kills adult fleas and is indicated for the treatment and prevention of flea infestations, the treatment and control of tick infestations, and the treatment and control of roundworm and hookworm infections in dogs and puppies 8 weeks of age and older, and weighing 2.8 ...
The best prescription alternatives to Simparica Trio include NexGard PLUS, Interceptor Plus with Bravecto or NexGard, and Credelio Quattro. These are made by trusted veterinary pharmaceutical companies like Boehringer Ingelheim, Elanco, Zoetis, and Virbac.
Simparica trio for dogs side effects: may cause neurological signs such as tremors, instability, and seizures in dogs with or without a history of neurological disorders.
Cedarwood oil solution (10 drops per 1 ounce of water) can be applied to both pets and the environment once to twice daily. Cedarwood mulch is a helpful deterrent for landscaping. For moderate infestations, Dr. Trish uses Revolution and for severe infestations, she recommends Nexgard.
Both products are safe for dogs when following directions and have been approved by the FDA to treat and prevent flea and tick infestations. While Simparica was trialed and not approved, Nexgard has not yet been evaluated for use in breeding, pregnant, or lactating dogs.
Dogs can also become exposed at toxic quantities through the ingestion or absorption of household insect sprays, foggers, and granules. Common brands of pyrethrins/pyrethroids include: Advantix™ Vectra 3D®
Simparica products are usually well tolerated in animals. There is minimal risk for overdose, side effects, or drug interactions if used as labeled or as directed by your veterinarian. Simparica products are available from your veterinarian or with a prescription from your veterinary pharmacy.
It's not uncommon for pets to experience mild side effects after taking medication like Simparica Trio. Lethargy can occur, but it's crucial to watch for any severe reactions such as vomiting or seizures. If your dog's lethargy continues or they show signs of distress, contacting your vet is the best course of action.
Heartworm Prevention: SIMPARICA TRIO should be administered at monthly intervals year-round or at least within one month of the animal's first seasonal exposure to mosquitoes and continuing until at least 1 month after the dog's last seasonal exposure.
However, Heartgard Plus Chewables cannot prevent the development of the adult stage. Use with caution for collies and other herding dog breeds. These breeds have been known to have adverse reactions to ivermectin at elevated dose levels.
Popular, vet-recommended flea and tick medicines for dogs include chewables Simparica and Credelio, plus Bravecto topical, all of which are prescription medicines. Your vet can help you choose the best flea and tick medication for your individual dog based on their specific needs.
Administer the new treatment exactly 30 days after the last one. If you switch from Heartgard Plus to Simparica Trio, your dog will now receive added flea and tick protection. Always monitor for side effects during the first dose transition.
What will my veterinarian recommend for flea and tick treatment? Veterinarians may recommend Simparica Trio, a monthly chewable tablet that prevents against heartworm, fleas, ticks, and intestinal parasites. Revolution Plus and Bravecto are also commonly recommended treatments.
Because heartworms must be eliminated before they reach this adult stage, it is extremely important that heartworm preventives be administered strictly on schedule (monthly for oral and topical products and every 6 months or 12 months for the injectable).
Alternative #5 – Natural Alternatives
Essential oils: Certain oils like cedar, lavender, and eucalyptus are reported to have parasite-repelling properties. Apple cider vinegar: Used as a spray or in drinking water to create an inhospitable environment for fleas.
Lavender oil and apple cider vinegar are two of the most common natural remedies for tick prevention for dogs. However, effectiveness will vary, so it's important to consult with your vet about what is best for your four-legged friend. Don't forget to consult your veterinarian before using any of these products.
“Ticks and mosquitoes are dangerous to the health of people as well as pets,” says veterinarian Dr. Jill Lopez. “For that reason, flea and tick protection is essential for all dogs and cats that live with you.”
10 Best Heartworm Medications for Dogs in 2025 [Vet-Recommended]
Simparica TRIO®, a canine endectocide manufactured by Zoetis, contains sarolaner, moxidectin, and pyrantel pamoate salt in an orally administered chewable tablet. These compounds are all toxic to both cats and dogs in sufficient amounts.
For pets with a history of seizures living in tick areas
You must consult your veterinarian. These pets may have a greater risk of side effects. Your vet can discuss alternative products, such as Advantix (for dogs only) or a Seresto collar (for dogs and cats).