In a laboratory study of spinosad alone, this active ingredient of Trifexis started to kill fleas within 30 minutes and killed 100% of fleas on dogs within 4 hours. Trifexis kills fleas before they can lay eggs.

Trifexis prevents heartworm disease in dogs by killing certain stages that develop after an infected mosquito bites a dog. It should also be administered for at least 3 months after your dog’s last exposure to mosquitoes for effective heartworm prevention. As with other heartworm preventatives, Trifexis does not kill adult heartworms. Speak to your veterinarian about treatment options if your dog is diagnosed with an adult heartworm infection.

• Trifexis is an oral monthly tablet that rapidly kills fleas on dogs and is effective in preventing heartworm disease and in treating and controlling of adult hookworm, adult roundworm and adult whipworm infections in dogs and puppies 8 weeks of age or older and 5 pounds of body weight and greater.
• Trifexis is approved by the FDA as safe and effective when used according to the label.
• Spinosad, one of the active ingredients in Trifexis, began to kill fleas on dogs 30 minutes after administration with 100% effectiveness within 4 hours in a well-controlled laboratory study.
• Trifexis continues to kill fleas for a full month after treatment.
• Dogs with signs of flea allergy dermatitis showed improvement as a direct result of eliminating the fleas.
• Trifexis is available in 5 strengths.

Give Trifexis with food for maximum effectiveness. Trifexis is a chewable tablet and may be given like a treat. Consult your veterinarian regarding the need for year-round administration of Trifexis. Use the included stick-on calendar labels to remember your dog's monthly dosing schedule or sign up for reminders that will help you remember an upcoming dose.

As with all medicines, sometimes side effects may occur. In some cases, dogs vomited after receiving Trifexis. If vomiting occurs within an hour of administration, redose with another full dose. During field studies, no severe or prolonged vomiting occurred. Additional adverse reactions observed in the clinical studies were itching, decreased activity, diarrhea, inflammation of the skin, redness of the skin, decreased appetite and redness of the ear. All reactions were regarded as mild.

Since the introduction of Trifexis, additional side effects reported are trembling/shaking, ataxia, seizures and hypersalivation.

Trifexis is a prescription medicine for dogs that should be purchased from a licensed veterinarian or pharmacy with a valid prescription.