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Product Info
How to Use
Customer Reviews
Product Info
What is Trifexis?

Trifexis is a chewable tablet that kills fleas and prevents infestations, protects against heartworms, and treats and controls adult hookworm, roundworm, and whipworm infections. Trifexis requires a prescription from your veterinarian.


Dogs (8 weeks of age and older and weighing at least 5 lbs)

  • Begins killing biting fleas within 30 minutes
  • Kills fleas before they can lay eggs
  • Prevents heartworm disease
  • Treats and controls roundworms, hookworms, and whipworms
  • Artificial beef flavor made from pork liver and hydrolyzed soy
  • Easy-to-administer chewable tablet
How it Works:

Spinosad, an active ingredient in Trifexis, starts to work within 30 minutes to kill fleas and has been proven to kill 100% of all biting fleas within 4 hours. Trifexis also kills flea eggs before they can mature, which helps to end the flea life cycle. Trifexis prevents heartworm disease by killing microfilariae and larvae from maturing into adult heartworms.


Serious adverse reactions have been reported following concomitant extra-label use of ivermectin with spinosad alone, one of the components of Trifexis chewable tablets. Use with caution in breeding females. The safe use of Trifexis in breeding males has not been evaluated. Use with caution in dogs with pre-existing epilepsy. Puppies less than 14 weeks of age may experience a higher rate of vomiting. Consult your veterinarian for pregnant or lactating dogs.

Brand Name:

Trifexis (Elanco Animal Health)

Generic Name:

Spinosad and Milbemycin oxime

What is the most important information I should know about Trifexis:

Trifexis is a prescription medication FDA approved for use in dogs 8 weeks of age or older and 5 lbs of body weight or more. Trifexis contains spinosad and milbemycin oxime and is indicated for the prevention of heartworm disease. Trifexis kills fleas and is indicated for the prevention and treatment of flea infestations, and the treatment and control of adult hookworm, adult roundworm, and adult whipworm infections. Trifexis is available in a pink box for dogs 5 to 10 lbs (140mg/2.3mg)), Orange box for dogs 10.1 to 20 lbs (270mg/4.5mg), Green box for dogs 20.1 to 40 lbs (560mg/9.3mg), Blue box for dogs 40.1 to 60 lbs (810mg/13.5mg), and Brown box for dogs 60.1 to 120 lbs (1620mg/27mg). For dogs over 120 lbs give the appropriate combination of tablets.

What is Trifexis:

Trifexis is a chewable, beef flavored tablet that is made out of pork liver and hydrolyzed soy and given to your dog once month to prevent heartworm, to prevent and treat flea infestations, and to treat and control adult hookworm, roundworm, and whipworm infections. Trifexis chewable tablets are for monthly use in dogs and puppies 8 weeks of age and older and 5 lbs of body weight or more.

What should I discuss with my veterinarian before giving Trifexis to my pet:

Tell your veterinarian if you are planning on breeding your pet. Tell your veterinarian if your dog has a history of seizures (epilepsy).

How should this medication be given:

Give Trifexis chewable tablets with food. Give Trifexis chewable tablets once a month. Trifexis chewable tablets may be chewed, offered in food, or administered like other tablet medications. If vomiting occurs within 1 hour of administration, redose the pet with another full dose. Store Trifexis at room temperature (68-77° F). Consult your veterinarian for pregnant or lactating dogs.

What happens if I miss a dose:

Give the missed dose with food as soon as you remember and resume a monthly dosing schedule.

What happens if I overdose the pet:

Overdose of this medication is unlikely. However, if an overdose is suspected, contact your veterinarian or veterinary emergency room. Symptoms of overdose that may occur include vomiting.

What should I avoid while giving Trifexis:

Your pet may maintain normal activities and interactions while being given Trifexis. The safe use of Trifexis chewable tablets in male dogs intended for breeding has not been established.

What are the possible side effects of Trifexis:

Side effects that may occur include vomiting. If vomiting occurs within one hour of administration, redose with another full dose. Other side effects may occur. Continue giving Trifexis chewable tablets and talk to your veterinarian if your pet experiences decreased appetite, lethargy or decreased activity, diarrhea, cough, increased thirst, vocalization, increased appetite, redness of the skin, hyperactivity and excessive salivation. Talk to your veterinarian about any side effect that seems unusual or especially bothersome to the pet.

What other drugs will affect Trifexis:

Talk to your veterinarian before giving any prescription or over the counter medications.

Where can I get more information:

Your pharmacist has additional information about Trifexis written for health professionals that you may read.

How to Use
  • Please view the chart below for the correct dosage of Trifexis for your dog.

Trifexis does not protect against ticks. To help control ticks, try the Preventic Tick Collar.

Dogs (Over 8 weeks of age)
5 - 10 lbs
Give one tablet (Pink label box)
10.1 - 20 lbs
Give one tablet (Orange label box)
20.1 - 40 lbs
Give one tablet (Green label box)
40.1 - 60 lbs
Give one tablet (Blue label box)
60.1 - 120 lbs
Give one tablet (Brown label box)
Over 120 lbs
Administer the appropriate combination of tablets
Do not use!
Do not use!

Should be stored at room temperature. Keep away from pets and children.

Trifexis for Dogs 5 to 10 lbs:
Active Ingredients per tablet
140 mg
Milbemycin oxime
2.3 mg
Trifexis for Dogs 10.1 to 20 lbs:
Active Ingredients per tablet
270 mg
Milbemycin oxime
4.5 mg
Trifexis for Dogs 20.1 to 40 lbs:
Active Ingredients per tablet
560 mg
Milbemycin oxime
9.3 mg
Trifexis for Dogs 40.1 to 60 lbs:
Active Ingredients per tablet
810 mg
Milbemycin oxime
13.5 mg
Trifexis for Dogs 60.1 to 120 lbs:
Active Ingredients per tablet
1620 mg
Milbemycin oxime
27 mg
Customer Reviews
Trifexis is rated 3.779 out of 5 by 457.
Rated 5 out of 5 by from Triflexis We are happy she is protected!!
Date published: 2016-06-22
Rated 5 out of 5 by from Trifexis saved the day! Our Annie is a year and 7 months old. When the time came to start Annie on flea and heart worm prevention we were super cautious. Annies sister had a near fatal reaction to a topical product and our Annie was her sister, so naturally we were concerned. Our vet suggested Trifexis and she has absolutely no problems at all.
Date published: 2016-06-07
Rated 5 out of 5 by from Wonderful! I have been administering this to my Great Dane puppy and my Great Dane adult. Neither have showed any negative side effects. They have been on this for almost 8 months, the all in one is convenient, I only wish it also did something for ticks! I won't use anything else for heart worm, this is wonderful. (And Great Danes have sensitive tummies!)
Date published: 2016-06-02
Rated 5 out of 5 by from Best for Fleas, Ticks, and Heartworm! We have used Trifexis for our Westie most of her 6 years and find that it works better than any other product or combination of products we've ever tried. Just one pill once a month and that's it. No fleas, no ticks and perfect heartworm coverage. We do give Sophie an anti-emetic along with it because she has a temperamental tummy, but our daughter's babies, a poodle and a pom, handle it perfectly with no nausea. Great product!
Date published: 2016-05-27
Rated 5 out of 5 by from Great product The first few times my Yorkie tried Trifexis she would mope around all day and at night would waking up trembling! So realizing it was from the medicine I decided to cut it in half and give her half a dose and the other half the next day! By doing this she is perfectly fine! The medicine works wonders, but it is hard trying to get her to take it!!! She is one spoiled fur baby!!
Date published: 2016-05-22
Rated 5 out of 5 by from Works great I've been using this for 2 years. I give with a meal, like the instructions say, and I've never had a flea on either of my pups. And my yard is very wooded, where you'd expect lots of fleas. We also go to the vet every 6 months & Trifexis has proven effective against heartworms, as well. The dogs don't like the taste but smothering the pill in peanut butter does the trick.
Date published: 2016-05-22
Rated 5 out of 5 by from Great "all in one" med for the worms and fleas. I first tried Trifexis buying 3 doses from my vet. It was pretty expensive, about $25 a dose. After seeing how well it worked, I decided to purchase more at a great price through petmeds. My dog ate it happily the first one or two times, after that she wouldn't eat it like a treat anymore. That problem was easily fixed by crushing it up a little bit then mixing it with wet cat food (which she loves! lol). Haven't had any other issues with it since. Excellent product!
Date published: 2016-05-12
Rated 3 out of 5 by from Mixed Reactions I have two 60lb German Shepard mixes. My girl (blonde dog) is about 5 years old and Luca is about a year. I gave them both this medication and it worked great. Even when everyone around me was complaining about flea problems in the apartments, we stayed flea free! That was my first successful summer keeping fleas off dogs. They'd take the pills like treats and it was fantastic. The second summer, however, my perfectly healthy girl started having a reaction. We did just move to a new place, so it could have been something there. I gave them each their dose as usually, and Nyx started having what appeared to be minor seizures. The vet decided to take them both off and try something else.. Nyx had multiple seizures that month and for a while they got really bad. I had friends come over and babysit while I was at work just in case she took a turn for the worse, after that last month though, she never had another. They weren't life threatening and I was probably overreacting but my dogs are my babies and if I can have them on something that doesn't cause side effects, I'd prefer that even if it might not work as well
Date published: 2016-05-04
  • 2016-06-26T06:00CST
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I still have some but they are over a year old can I still use them

Asked by: veeda
If your dog has not missed any monthly treatments, check the expiration date on your Trifexis to see if it is still good. Most product has an expiration date that is over a year from when our hospital purchases it from the manufacturer.
Answered by: SuztCVT
Date published: 2016-06-07

I have a 16 week old lab puppy who weighs 30 lbs. what size Trifkexus should I buy as he will go past the 40 lb within two months?

Asked by: Annie
Please check with your Pet's Veterinarian as to what the proper medication and dosage should be based on your pets age and size.
Answered by: Pharmacy Manager
Date published: 2016-04-25

How soon can I give my yorkie trifexis? 

Asked by: Rosie
Trifexis is safe to administer in pets 8 weeks or older who weigh at least 5 pounds.
Answered by: Lisa M
Date published: 2016-04-25

does this product also protect against ticks?

Asked by: Sydd
Trifexis does not provide protection against ticks.
Answered by: Lisa M
Date published: 2016-06-16

I have had my local Vet prescribe Trifexis and now he wants $140 refill. Can I scan my last scrip and send it to you for filling?

Asked by: John
We will contact your pet's clinic for the approval once you order Trifexis. We can only accept original prescription by mail or the vet may scan or email us the approval. We contact the vet for you once you place the order and most veterinarians respond within 24 hours and your pets prescription will ship out.
Answered by: Laura PetMed Pro
Date published: 2016-06-16

Will my dog need to be tested for heartworms yearly while on trifexis?

Asked by: Sharone
Since Trifexis is a prescription medication, your vet will need to perform a yearly exam and any required tests, including a heartworm test, depending upon your state's requirements. In Florida, an annual heartworm test is required.
Answered by: SuzyCVT
Date published: 2016-06-16

is it ok to cut the trifexis pill in half or to quarter it but give

but give the full pill cut in half or quartered?
Asked by: Carm
Some dogs tolerate the medication a little better if given it halved or quartered so long as the entire pill is given within an hour or two. Letting the pill "air out" for a couple of hours has been known to improve the palatability of the tablet for those very picky dogs.
Answered by: SuzyCVT
Date published: 2016-06-16

How many pills total will I be receiving?

Is it 6 packs of 6 pills or 6 pills total?
Asked by: Anonymous
A 6-pack always means one package of 6 tablets.
Answered by: SuzyCVT
Date published: 2016-04-30
  • 2016-06-26T06:06CST
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