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Trifexis Chewable Tablets for Dogs Rx

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Questions & Answers

Product Description

Trifexis® for Dogs is a once a month chewable tablet that kills fleas and prevents heartworms, and treats and controls adult roundworm, hookworm, and whipworm infections. Checkout the Allivet Heartworm Comparison chart to compare which heartworm prevention products.

Who is Trifexis Chewable Tablets for Dogs for?

Trifexis is for dogs and puppies 8 weeks of age or older. Trifexis should not be used on puppies or dogs under 5 lbs.

Why use Trifexis Chewable Tablets for Dogs?

  • Trifexis chewable tablets kill fleas before they lay eggs and kill biting fleas within 30 minutes of administration.
  • Trifexis treats and controls roundworms, hookworms, and whipworms.
  • Trifexis prevents heartworm disease and kills immature heartworms.
  • Trifexis is the most prescribed combo parasite protection
  • Beef flavored tablet that dogs love.

How does Trifexis Chewable Tablets for Dogs work?

  • In one monthly tablet, Trifexis prevents flea infestations and protects your dog from parasites.
  • Spinosad (primary ingredient) kills adult fleas, preventing flea infestation.
  • Spinosad targets activation of nicotinic acetylcholine receptors (nAChRs) in insects.
  • Begins working in 30 minutes.
  • Proven to kill 100% of all biting fleas.
  • Milbemycin Oxime (active ingredient) is used to prevent heartworms and kill immature heartworms.
  • Milbemycin Oxime kills adult hookworms, roundworms, and whipworms.


Elanco Animal Health

Active ingredient(s):

Spinosad and Milbemycin Oxime

How is Trifexis Chewable Tablets for Dogs sold?

Trifexis cheweable tablets for dogs are sold in 1, 3, 6, or 12 month supplies based on your dog's weight. Boxes are color coded to weight.
  • Trifexis Pink: 5-10 lbs
  • Trifexis Orange: 10-20 lbs
  • Trifexis Green: 20-40 lbs
  • Trifexis Blue: 40-60 lbs
  • Trifexis Brown: 60-120 lbs

What are the side effects of Trifexis Chewable Tablets for Dogs?

The most common adverse reactions in clinical trials were:
  • Vomiting
  • Diarrhea
  • Lethargy
  • Pruritus (itchy skin)
You may give your dog another dose if vomiting occurs with an hour of dose. Puppies younger than 14 weeks of age may experience a higher rate of vomiting.

What special precautions are there?

Before starting Trifexis, your dog should be tested for heartworm infestation.
Use with caution in dogs with pre-existing epilepsy.
Trifexis has not been evaluated for safe use in breeding females.

What to do if overdose?

In the event of overdose or adverse reaction while using Trifexis, contact your closest emergency pet hospital.

How can I store Trifexis Chewable Tablets for Dogs?

Store at room temperature between 68-77° F.

Helpful Tips:

For full heartworm prevention, ensure your dog gets three monthly doses after his/her last exposure to mosquitoes.
Trifexis doesn't require you to isolate your dog from other pets during treatment.

Pharmacists are standing by to offer Pet Parent counseling regarding prescription medication purchased from Allivet before and after dispensing. Pharmacists on duty are available Monday-Friday, 9:30AM - 5:30PM EST and will be on call Saturday 12:00PM - 4:00PM EST for consultation.


Trifexis is a prescribed pet medication for the prevention of fleas and parasites such as roundworm, hookworm and heartworm. Follow your veterinarian's directions on when to give this medication. If you are advised to give it seasonally for heartworm prevention, remember to give it during the mosquito season and 3 months beyond, preferably on the same date each month.

Trifexis should be used as recommended by your veterinarian. If you have difficulty giving the medication to your dog, contact your veterinarian. 
Dosages of Trifexis by Weight for Dogs Over 8 Weeks of Age

Weight                  /                       Dosage
5-10 lbs                             1 Tab (Pink Label box)
10.1 - 20 lbs                    1 Tab (Orange Label box)
20.1 - 40 lbs                     1 Tab (Green Label box)
40.1 - 60 lbs                     1 Tab (Blue Label box)
60.1 - 120 lbs                  1 Tab (Brown Label box)
Over 120 lbs                    Vet’s Prescribed Dosage

If you do not administer Trifexis monthly throughout the year, the final dose must be given no fewer than three months following the last exposure to mosquitoes. Please speak with your vet for any question regarding Trifexis dosage or missed dosages. 

Main Ingredients

Trifexis is manufactured by Elanco Animal Health and contains the following active ingredients:

Active Ingredients           /             Amount per Tablet
Spinosad                                                140 mg
Milbemycin Oxime                                2.3 mg

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Trifexis Chewable Tablets for Dogs

Frequently Asked Questions about Trifexis

What does Trifexis do for dogs?

Why is Trifexis prescription only?

How much is Trifexis at the vet?

What is the generic for Trifexis?

When does Trifexis expire?

How quickly does Trifexis work?

How often do you give Trifexis to your dog?

Why is Trifexis not working?

Does Trifexis make dogs sick?

Why is Trifexis bad for your dog?

Is it ok to crush Trifexis?

Do dogs have to chew Trifexis?

Do fleas have to bite for Trifexis to work?

Can you bathe a dog after Trifexis?

Can dogs still get fleas on Trifexis?

Will Trifexis kill ear mites?

Will Trifexis kill heartworms?

Will Trifexis kill tapeworms?

Will Trifexis kill roundworms?

Can Trifexis be used on cats?

Can Trifexis be given to pregnant dogs?

Can Trifexis cause elevated liver enzymes?

Can Trifexis cause diarrhea?

Can Trifexis cause itching?

Can I give Trifexis without food?

Can I give Trifexis without heartworm test?

Can Trifexis be cut in half?

Can you answer these questions?

We have a large and a small dog. Can I just order the packet for large dogs and divide one tablet into 3 pieces/doses for my smaller dog? Large dog is 90 lbs and small dog is 17 lbs.

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