Trifexis Chewable Tablet for Dogs, 20.1-40 lbs, (Green Box), 6 Chewable Tablets (6-mos. supply)
Prescription Item
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Your furry friend must have a current heartworm test result on file with your veterinarian in order to be prescribed heartworm medication. Please visit your veterinarian to have this test performed annually to protect your four-legged friend. Trifexis (spinosad + milbemycin oxime) is the monthly, beef-flavored tablet prescribed to kill fleas and prevent flea infestations, prevent heartworm disease, and treat and control adult hookworm, roundworm and whipworm infections in dogs. With flea medicine, heartworm preventive and intestinal parasite control in one, get the peace of mind that comes from protecting your canine companion.
UsesTrifexis prevents heartworm disease. Trifexis kills fleas and prevents flea infestations, and treats and controls adult hookworm, roundworm and whipworm infections in dogs and puppies 8 weeks and older and 5 pounds or more.
Possible Side EffectsWhen used as prescribed, side effects while using Trifexis are rare. Symptoms of GI distress and skin irritation can occur. Vomiting, diarrhea, lethargy, lack of appetite, and itching and reddening of the skin have been reported. Vomiting may be more likely in puppies under 14 weeks of age. If your dog is truly allergic to Trifexis or to the dying of parasites, she may exhibit symptoms such as facial swelling, hives, scratching, sudden onset of diarrhea, vomiting, shock, seizures, pale gums, cold limbs, or coma. If your dog experiences any of these symptoms, call your veterinarian or a local emergency veterinarian immediately.
Drug & Food InteractionsAlways communicate with your veterinarian about any medications, vitamins, or supplements your dog is already taking. Some serious adverse reactions have been documented when used with other spinosad and ivermectin medications simultaneously. No known food interactions have been reported.
Precautions
The use of ivermectin at higher than FDA approved doses at the same time as Trifexis can result in serious side effects. Treatment with fewer than three monthly doses after the last exposure to mosquitoes may not provide complete heartworm prevention. Prior to administration of Trifexis, dogs should be tested for existing
heartworm infection. 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. The most common adverse reactions reported are vomiting, decreased activity, itching, decreased appetite, and diarrhea. To ensure heartworm prevention, observe your dog for one hour after administration. If vomiting occurs within an hour of administration, re-dose with another full dose. Puppies less than 14 weeks of age may experience a higher rate of vomiting. For complete safety information, please see Trifexis product label or ask your veterinarian.
Dosage Chart
Color on Box | Weight Range | Strength | Dosage | Product Page |
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Magenta | 5-10 lbs | 140 mg Spinosad & 2.3 mg Milbemycin Oxime | Administer orally once a month | ✓-Click Here |
Orange | 10.1-20 lbs | 270 mg Spinosad & 4.5 mg Milbemycin Oxime | Administer orally once a month | ✓-Click Here |
Green | 20.1-40 lbs | 560 mg Spinosad & 9.3 mg Milbemycin Oxime | Administer orally once a month | ✓-Click Here |
Blue | 40.1-60 lbs | 810 mg Spinosad & 13.5 mg Milbemycin Oxime | Administer orally once a month | ✓-Click Here |
Brown | 60.1-120 lbs | 1620 mg Spinosad & 27 mg Milbemycin Oxime | Administer orally once a month | ✓-Click Here |
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Item Number146169
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Common Brand Name(s)Trifexis, Comfortis
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For Use WithDogs
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Generic NameSpinosad, Milbemycin Oxime
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Administration FormOral
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BrandElanco
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Breed SizeSmall Breeds, Medium Breeds
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Product FormChewable Tablet
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Strength560 mg Spinosad and 9.3 mg Milbemycin Oxime
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Health ConditionHeartworms, Fleas, Hookworms, Roundworms, Whipworms
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Drug TypeParasiticide
560 mg Spinosad and 9.3 mg Milbemycin Oxime.
Trifexis is a beef-flavored chewable tablet and may be given from your hand, mixed in with food or placed in a treat. Give Trifexis with food for maximum effectiveness. To ensure heartworm prevention, observe your dog for one hour after dosing. If your dog vomits within an hour of administration, re-dose with another full dose.
Storage InstructionsStore at controlled room temperatures between 68° - 77°F.
What Is Trifexis (Spinosad + Milbemycin Oxime), And What Does It Protect Against?
Trifexis is a monthly, chewable tablet for dogs. Trifexis kills fleas and prevents flea infestations on dogs, treats and controls adult hookworm*, whipworm and roundworm infections, and prevents heartworm disease. Trifexis is for use in dogs and puppies 8 weeks of age or older and 5 pounds of body weight or greater. If you do not administer Trifexis monthly throughout the year, continue administering the medication for at least three months following the last exposure to mosquitoes.
What Are Some Of The Benefits Of Trifexis?
- Trifexis is an oral monthly product that rapidly kills fleas on dogs and is effective in preventing heartworm disease and treatment and control of adult hookworm (A. caninum), 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 in erythema, papules, scaling, alopecia, dermatitis/pyodermatitis and pruritus (itching) as a direct result of eliminating the fleas.
- Trifexis is available in five strengths. Each tablet is formulated to provide a minimum dosage of 13.5 mg/lb (30 mg/kg) spinosad and 0.2 mg/lb (0.5 mg/kg) milbemycin oxime according to body weight.
How Well Does Trifexis Work?
- In a well-controlled laboratory study, Trifexis was 100% effective against induced heartworm infections in dogs when administered for three consecutive monthly doses.
- In well-controlled laboratory studies, a single dose of Trifexis at labeled dose was effective in removing roundworms, whipworms and hookworms (A. caninum).
- In a well-controlled laboratory study, spinosad alone began to kill fleas 30 minutes after administration and demonstrated 100% effectiveness within 4 hours.
- Spinosad kills fleas on dogs before they can lay eggs. If a severe environmental infestation exists, fleas may persist for a period of time after dose administration due to the emergence of adult fleas from pupae already in the environment. In field studies conducted in households with existing flea infestations of varying severity, flea reductions of 98.0 to 99.8% were observed during the course of three monthly treatments with spinosad alone. Dogs with signs of flea allergy dermatitis showed improvement in erythema, papules, scaling, alopecia, dermatitis/pyodermatitis and pruritus (itching) as a direct result of eliminating the fleas.
What Are The Active Ingredients In Trifexis Chewable Tablets?
Spinosad and milbemycin oxime are the two active ingredients in Trifexis.
What Is The Flavoring In Trifexis Tablets?
The flavoring in Trifexis comes from artificial beef flavoring made from pork-based proteins and hydrolyzed soy.
What Is The Flavoring In Trifexis Tablets?
The flavoring in Trifexis comes from artificial beef flavoring made from pork-based proteins and hydrolyzed soy.1
Is Trifexis Fda Approved?
Yes, Trifexis is a prescription medicine approved by the Food and Drug Administration and should be obtained only through a licensed veterinarian with whom you have a proper veterinarian-client-pet relationship.
Is It Safe To Give My Breeding Dogs Trifexis?
Ask your veterinarian about the use of Trifexis prior to use in breeding females. The safe use of Trifexis in male dogs intended for breeding has not been evaluated.
What Side Effects Might Occur With Trifexis?
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.
What Is The Most Common Adverse Event With Trifexis?
The most common adverse reactions based on post-approval adverse drug event reporting are vomiting, depression/lethargy, pruritus, anorexia, trembling/shaking, atazia, seizures, hypersalivation and skin reddening.
How Quickly Will Trifexis Kill Fleas?
In a laboratory study of spinosad alone, this active ingredient of Trifexis started to kill fleas within 30 minutes and killed 100% of the fleas on dogs within 4 hours. Trifexis kills fleas before they can lay eggs.
Will Trifexis Kill Heartworms?
Trifexis prevents heartworm disease in dogs by killing certain stages that develop after an infected mosquito bites a dog. As with other heartworm preventives, Trifexis does not kill adult heartworms. Speak to your veterinarian about treatment options if your dog is diagnosed with an adult heartworm infection.
Which Heartworm Lifecycle Stage Does Trifexis Control?
Trifexis acts in the same way as other monthly heartworm preventives, by killing L3 and L4 larval stages before they molt to the final adult stage.
Does Trifexis Protect Against Ticks?
No, Trifexis is not labeled to kill or repel ticks. Trifexis is labeled for the prevention of heartworm disease on dogs, to kill adult fleas on dogs and to treat and control adult hookworm, roundworm and whipworm infections in dogs. There are no known contraindications between Trifexis and medications commonly used against ticks.
My Dog Has Tapeworms. Will Trifexis Get Rid Of Those?
No, Trifexis will not treat a tapeworm infection. Trifexis is indicated for the prevention of heartworm disease in dogs, for the prevention and treatment of flea infestations on dogs and the treatment and control 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 or greater.
Powerful Protection
Trifexis gives your dog broad spectrum protection against five common canine parasites: fleas, heartworm disease, hookworms, roundworms, and whipworms. Just one tablet provides protection that you can rely on all month long.


Neutralize Threats
Trifexis works 24/7 to kill fleas and prevent reinfestation, but the protection doesn’t stop there. It also works to prevent heartworm disease and to treat and control adult hookworm, roundworm and whipworm infections to keep your dog protected. Why settle for anything less?
Flea Treatment and Prevention
Trifexis starts killing fleas in as little as 30 minutes, completely eliminating all adult fleas within 4 hours. And it keeps on killing fleas all month, eradicating newcomers before they can ever lay eggs and cause a new infestation.


Beef-Flavored Tablet
All this powerful coverage comes in a compact and easy-to-administer beef-flavored tablet. Trifexis can be given directly by hand, placed in your dog's food bowl, or hidden in a yummy treat. Administer with food for maximum effectiveness.
Dosed By Weight
Trifexis comes in five different strengths to provide custom-tailored dosing for a wide range of dogs. Just one tablet provides the correct amount your pup needs to protect him for a whole month from 5 different types of parasites. Trifexis works for dogs 8 weeks and older, with dosing for dogs from 5 pounds to 120 pounds—and beyond!

Product Guide
Trifexis offers protection for dogs in most sizes and weights. Choose the option best suited for your furry friend
5 - 10 LBS
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10.1 - 20 LBS
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20.1 - 40 LBS
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40.1 - 60 LBS
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60.1 - 120 LBS
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Indication
Trifexis prevents heartworm disease. Trifexis kills fleas and prevents flea infestations, and treats and controls adult hookworm, roundworm and whipworm infections in dogs and puppies 8 weeks and older and 5 pounds or more.
Important Safety Information
The use of ivermectin at higher than FDA-approved doses at the same time as Trifexis can result in serious side effects. Treatment with fewer than three monthly doses after the last exposure to mosquitoes may not provide complete heartworm prevention. Prior to administration of Trifexis, dogs should be tested for existing heartworm infection. 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. The most common adverse reactions reported are vomiting, decreased activity, itching, decreased appetite, and diarrhea. To ensure heartworm prevention, observe your dog for one hour after administration. If vomiting occurs within an hour of administration, redose with another full dose. Puppies less than 14 weeks of age may experience a higher rate of vomiting. For complete safety information, please see Trifexis product label or ask your veterinarian.
About Trifexis
Trifexis is a once-a-month, beef-flavored tablet that provides broad protection against a range of parasites. It kills fleas, prevents flea infestations, prevents heartworm disease, and treats and controls adult hookworm, roundworm, and whipworm infections. Protect your dog with convenient parasite protection that lasts all month long.

Customer Reviews
97% Recommend
97% of reviewersrecommend this product
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152 Reviews
Showing 1-10 of 152 Reviews
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This Works!
By Snowbird on Feb 3, 2021
Our vet at home agreed with the change from a topical product to this chewable for our dog since fleas appeared after use with the former while we are away in Florida.I was surprised as I read Trifexis can begin to treat fleas within 4 hours,and with continuing inspections we can say how amazed we are with this product! Our Welsh Terrier is no longer scratching, and we are all so relieved as we inspect him and find nothing moving in his fur. We are all sleeping through the night again! The representative at Chewy helped get all the needed information from us when we called, she checked our vet in another state, and within a couple of days we were all in the mend! Thank you Julia!
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Trifexis fan!
By Lolli on Feb 2, 2021
My dog Lolli is a Florida pooch who confidently faces the mosquito season! WHY? She has Trifexis! It's a terrific product that offers defense against heartworms, and treats and controls adult hookworm, roundworm, and whipworm infections. And, she's happier still because the terrific people at Chewy make it affordable and accessible with delivery right to the door!
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Price for Trifexis
By Donna on Feb 1, 2021
The price of each box started out being a fair price, but that was after a $50 new customer discount, BUT then my Vet charged me $ 15.00 per box, so an extra $ 30 total for calling in the prescription. So, the next time I would order it from you, it will be more expensive than what I can get from the Vet who carries it locally !!
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Chewy makes life easier.
By Snookum on Feb 12, 2021
My dog and I reside in two different locations. Our vet in the midwest doesn't carry the trifexis that we use when we're home on the west coast, so it gets complicated when we run out. Chewy makes it so much easier .
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Satisfactory
By Callie on Feb 13, 2021
There was a lot of confusion in the beginning on getting this prescription filled. Very frustrating. However, in the end, Chewy did try to make things right and I appreciate that.
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Best anti-flea and tick supplement on the market so far!
By Oleny on Nov 6, 2020
I have had all four of my dogs on Trifexis for the past 8 years and I am so grateful for its reliable efficacy! I have been offered a few other flea and tick prevention options through the vet but I keep sticking with Trifexis! It has not let me down and I can take my dogs to the dog beach, on a hike through any type of terrain, and allow them to meet other pups confident and knowing that my dogs will not catch fleas...such as is naturally prone to occur when they are off of Trifexis. Yes, it is pretty expensive to buy a year supply for four dogs or even just one or two, but I really recommend that browsing customers give it a try and see buying Trifexis as an investment...they should not be I have had all four of my dogs on Trifexis for the past 8 years and I am so grateful for its reliable efficacy! I have been offered a few other flea and tick prevention options through the vet but I keep sticking with Trifexis! It has not let me down and I can take my dogs to the dog beach, on a hike through any type of terrain, and allow them to meet other pups confident and knowing that my dogs will not catch fleas...such as is naturally prone to occur when they are off of Trifexis. Yes, it is pretty expensive to buy a year supply for four dogs or even just one or two, but I really recommend that browsing customers give it a try and see buying Trifexis as an investment...they should not be dissatisfied! It is so expensive to de-flea and tick our dogs along with every area throughout the home and vehicle/s...but in my opinion, Trifexis is truly an investment in your dog's health and your sanity worth making :) … more
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Fleas are gone
By Mina on Jan 21, 2021
We live in the middle of nowhere and we tried everything,but our Pup still got fleas!Our Vet recommended Trifexis and it worked!NO FLEAS since years!Its wonderful!
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Positive Heartworm after a year of Trifexis
By Mahal on Nov 10, 2020
Our dog was tested negative for heart worm before taking this trifexis. She was on it for a year. We thought this was the best but on her annual exam , she was tested heartworm positive. Apparently it didn't work even with close supervision while taking this monthly.
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Great Meds
By Corgimum on Dec 2, 2020
Awesome convenient way to get meds delivered! I'm currently 38 weeks pregnant (and quarantined) and this was the best and easiest way to take care of my fur babies, thanks Chewy!
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Took Forever
By WillyJ on Oct 9, 2020
I have never had an issue with the product itself, seems to do what it says. The problem I had this time was it took chewy over 2 weeks to get it to me. This is a time sensitive medicine causing me to have to go and get extra from my vet while I waited for this prescription to get filled. I hope this is a one time event.