Spinosad and Milbemycin Oxime
Trifexis is a monthly chewable tablet for dogs that provides combined protection against fleas, heartworm disease, and common intestinal parasites. It is prescribed by veterinarians for use in dogs and puppies over 8 weeks of age and weighing at least 5 pounds.
A monthly preventive medication for dogs that protects against fleas, heartworm disease, and intestinal worms.
Key facts at a glance
- RxNorm
- 1372727
- Generic
- Trifexis
- Class
- brand-name
- Brands
- —
- Availability
- rx
- Lactation
- unknown
- Routes
- —
- Forms
- —
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Prevents heartworm disease caused by Dirofilaria immitis, treats and controls flea infestations (Ctenocephalides felis), and controls and treats intestinal parasites including roundworms (Toxocara canis, Toxascaris leonina), hookworms (Ancylostoma caninum), and whipworms (Trichuris vulpis).
Contains two active ingredients: spinosad, an insecticide that kills fleas by causing hyperexcitation of their nervous system; and milbemycin oxime, an anthelmintic that works by disrupting nerve transmission in parasitic invertebrates, causing paralysis and death of susceptible parasites.
Must be given with food for optimal absorption. Should be used with caution in dogs with a history of seizures or neurological disorders. Does not protect against ticks. Heartworm testing is recommended before starting and during use. Keep out of reach of cats as spinosad can be toxic to felines. Consult your veterinarian for complete safety information.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 29, 2026. · Read our editorial policy