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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 Trifexis 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 3.9 out of 5 by 526.
Rated 4 out of 5 by from Trifexis I have used Trifexis for several years now and I am very happy with this product. I absolutely love it! And so do my dogs.
Date published: 2017-02-17
Rated 4 out of 5 by from Trifexis Fantastic!!! All my german shepherds need to protect them from all kind of worms.
Date published: 2017-02-17
Rated 1 out of 5 by from Trifexis I purchased this 2 weeks ago and I am very happy with it. Also, the price is great.
Date published: 2017-02-09
Rated 5 out of 5 by from Great preventative meds/ Triflexis keeps my pal running without pests.
Date published: 2017-02-09
Rated 5 out of 5 by from Love this product We have used this for quite some time and have had excellent results! I would highly recommend Trifexis!
Date published: 2017-02-05
Rated 5 out of 5 by from Trifexis Maggie has been taking trifexis for years now and she's wonderful! I'm very pleased with this medicine and grateful!
Date published: 2017-02-04
Rated 5 out of 5 by from Trifexis Our vet stopped selling "Trifexis". Due to complaints from others stating that their pet did not react will with the meds. We'll, it is a big pill and it doesn't look to appetizing even for me. Our vet also cautioned us at the beginning (last year), some animals didn't like it. So, what I did from the beginning is to smash up the pill and mixed it up with her wet food. We'll, my dog has never had an issue with it. Maybe it will work for you to. Thanks
Date published: 2017-01-29
Rated 5 out of 5 by from Fast! I was very worried about buying Trifexis due to the high price - but it has been working! I was very surprised and pleased with how quickly it worked!
Date published: 2017-01-28
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My 6 month old puppy (15 lbs) just took her comfortis and also stole another dog's trifexis (40-60 lbs) will this be a trip to the vet?

Asked by: Ford
Hello Ford, I know that is alarming to find out, as that is a lot. Fortunately both these drugs contain the same active ingredient (spinosad) for fleas and they are both normally well tolerated. I would recommend watching your pet and calling your vet immediately if you see anything unusual or any serious side effects happening, such as vomiting or seizures. The main side effect in both these drugs is vomiting. You can then continue with the normal monthly regimen. Hope this helps. Thanks, Pharmacy student intern
Answered by: Trey W
Date published: 2017-02-16

Will it kill ticks

Asked by: Big Daddy
Will it kill flea eggs
Answered by: Bonnie
Date published: 2017-02-11

Is it safe to touch trifexus to give to my dog while pregnant? 

Asked by: Michelle87
The active ingredients of Trifexis are not absorbed through the skin and as long as you wash your hands after giving the tablet to your dog, you and your baby should be fine.
Answered by: SuzyCVT
Date published: 2017-02-09

gave my newly adopted 14lbs dog-1/2 the 10 - 20lbs tablet in the am and the other 1/2 pm. It did not seem to do a good job killing the many fleas, he has had several baths as well. It has been 7 days since administration. Can I give him again?

Asked by: jennifer
Splitting the tablet in half and giving it at different times of the day is not recommended to prevent heartworms. You may split the tablet for ease of administration, but the entire tablet should be ingested within 15 minutes. The flea control part may or may not be affected by splitting the dose. I would think that should still be good as that part stays in the system a full 30 days. If your dog has a severe flea infestation, one treatment will likely not be sufficient to eliminate the problem as for every adult flea, there are hundreds or more eggs and cocooned larva in the environment. A minimum of 3 months of treatment is necessary to see major improvement for severe flea infestations. It is too soon to give another Trifexis tablet so you may need to supplement your flea control with baths or sprays. Using a topical monthly flea treatment in addition to the Trifexis may be too much for your little dog.
Answered by: SuzyCVT
Date published: 2017-02-07

I have a dog that is 16 pounds then a dog that is 25 pounds. .I was wanting to get a box of trifexis and split between them to save money..will the ten to twenty pound pill work on my 25 pound dog at all?

Asked by: Barb
Using the 10-20 pound dose on your 25 pound dog will not be sufficient to prevent heartworms. You also can not split the larger tablet in half to use the higher strength on your smaller dog as the active ingredients are not evenly distributed in the tablet. You will have to purchase the appropriate size for each pet. Check with your veterinarian to see if he/she sells the tablets individually so your initial expense is not as great.
Answered by: SuzyCVT
Date published: 2017-02-03

How much for s/H charge

Asked by: gail
As it states, shipping is free for this product.
Answered by: SuzyCVT
Date published: 2017-01-31

Is Trifexis used for heart worm and flea and tick prevention?

Asked by: Heather12
Trifexis is used to prevent heartworms, deworm for intestinal parasites and kill fleas. It does not kill ticks.
Answered by: SuzyCVT
Date published: 2017-01-31

Can my dog get sick after applying this medication. I put it on a couple days so and she won't eat has diarrhea and throwing up

Asked by: Brevere
Trifexis is a chewable tablet and is not "applied". It may make a dog nauseous, especially if given on an empty stomach, but most dogs recover without issue. I recommend you verify what product you have given and have your pet seen by your veterinarian.
Answered by: SuzyCVT
Date published: 2017-01-24
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