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Comfortis

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About this product

What is Comfortis (spinosad)?

Comfortis is the first FDA-approved, chewable beef-flavored tablet (derived from pork protein and hydrolyzed soy) that kills fleas and prevents flea infestations on dogs and cats for a full month. Comfortis for Dogs & Cats requires a prescription from your veterinarian.

For:

Dogs & Cats (14 weeks of age or older)

Benefits:

  • Starts killing fleas within 30 minutes
  • Lasts a full month
  • Kills fleas before they can lay eggs
  • Comes in a convenient chewable, beef-flavored tablet
  • Spinosad, the active ingredient in Comfortis, is environmentally friendly

Comfortis is the #1 recommended Rx Flea-only medication for dogs and cats

How does Comfortis work?

The active ingredient in Comfortis (Spinosad) kills fleas by causing excitation of the insect's nervous system, leading to paralysis and rapid death.

Cautions:

Side effects may occur, including vomiting. If your pet is experiencing loss of appetite, lethargy, or any other difference in behavior, contact your veterinarian. The FDA has received reports of adverse reactions in dogs receiving the drug Comfortis (spinosad) concurrently with high, extra-label doses of ivermectin. Dogs receiving extra-label doses of ivermectin to treat non-responsive demodectic mange and other conditions have developed signs of ivermectin toxicity. Ivermectin is an ingredient found in heartworm preventatives such as Heartgard Plus, Heartgard, Iverhart Plus and Ivomec. In cats, the most common adverse reaction recorded in clinical trials was vomiting. Other adverse reactions were: lethargy, decreased appetite, weight loss, and diarrhea. Use with caution with concomitant extra-label use of ivermectin. For complete safety information, see product label.

Brand Name:

Comfortis (Elanco)

Generic Name:

Spinosad

What is the most important information I should know about Comfortis?

Comfortis is a prescription medication FDA approved for use in dogs and puppies and cats and kittens 14 weeks of age or older to kill fleas and prevent flea infestations for one month. Comfortis is available in a Pink box for dogs 5 to 10 lbs and cats 4.1-6 lbs (140 mg), Orange box for dogs 10.1 to 20 lbs and cats 6.1-12 lbs (270 mg), Green box for dogs 20.1 to 40 lbs and cats 12.1-24 (560 mg), Blue box for dogs 40.1 to 60 lbs (810 mg), and Brown box for dogs 60.1 to 120 lbs (1620 mg). Please note: Cats over 24 lbs should be administered the appropriate combination of tablets.

What should I discuss with my veterinarian before giving Comfortis to my pet?

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

How should Comfortis be given?

Give Comfortis chewable tablets with food. Give Comfortis chewable tablets once a month. Comfortis 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 Comfortis at room temperature (68-77 F)

Comfortis is an easy-to-give oral treatment that doesn't make a mess

What are the potential side effects of Comfortis?

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 Comfortis chewable tablets and talk to your veterinarian if your pet experiences decreased appetite, lethargy or decreased activity, diarrhea, incoordination, weight loss, cough, increased thirst, vocalization, increased appetite, redness of the skin, hyperactivity and excessive salivation. Following concomitant extra-label use of ivermectin with Comfortis, some dogs have experienced the following clinical signs: trembling/twitching, salivation/drooling, seizures, incoordination, excessive dilation of pupils, blindness and disorientation. Post-approval experience continues to support the safety of Comfortis when used concurrently with heartworm preventatives according to label directions.Talk to your veterinarian about any side effect that seems unusual or especially bothersome to the pet.

What happens if I miss giving a dose of Comfortis?

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

What happens if I overdose my pet on Comfortis?

Contact your veterinarian immediately.

What should I avoid while giving Comfortis?

Your pet may maintain normal activities and interactions while being given Comfortis. The safe use of Comfortis in breeding, pregnant, or lactating cats and dogs has not been evaluated.

What other drugs will affect Comfortis?

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

Comfortis is trusted by vets and has been prescribed over 90 million times

See more

Comfortis Directions:

  • Comfortis is a prescription medication used in dogs and cats to kill fleas and prevent flea infestations for 1 month.
  • Comfortis chewable tablets are beef flavored.
  • Comfortis can be given to dogs at least 14 weeks of age, weighing at least 5 lbs, and cats 14 weeks of age, weighing at least 4 lbs.
Tip:

If vomiting occurs within 1 hour of administration, redose the pet with another tablet.

Comfortis Dosage for Dogs:

Dogs/Puppies (14 weeks of age or older):
Weight Dosage
5-10 lbs (Pink Box) Give one 140 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications
10.1-20 lbs (Orange Box) Give one 270 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications
20.1-40 lbs (Green Box) Give one 560 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications
40.1-60 lbs (Blue Box)Give one 810 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications
60.1-120 lbs (Brown Box)Give one 1620 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications
Over 120 lbs Give the appropriate combination of tablets

Comfortis Dosage for Cats:

Cats/Kittens (14 weeks of age or older):
Weight Dosage
4.1-6 lbs (Pink Box) Give one 140 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications
6.1-12 lbs (Orange Box) Give one 270 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications
12.1-24 lbs (Green Box) Give one 560 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications
Over 24 lbs Give the appropriate combination of tablets
Comfortis Dosage for Horses:
Horses
Do not use!
Storage:

Store Comfortis at room temperature (68°-77° F).

Comfortis Ingredients:

Comfortis for Dogs: 5-10 lbs - Comfortis for Cats: 4.1-6 lbs (Pink Box)
Active IngredientAmount
Spinosad 140 mg
Comfortis for Dogs 10.1-20 lbs - Comfortis for Cats: 6.1-12 lbs (Orange Box)
Active IngredientAmount
Spinosad 270 mg
Comfortis for Dogs 20.1-40 lbs - Comfortis for Cats: 12.1-24 lbs (Green Box)
Active IngredientAmount
Spinosad 560 mg
Comfortis for Dogs 40.1-60 lbs (Blue Box)
Active IngredientAmount
Spinosad 810 mg
Comfortis for Dogs 60.1-120 lbs (Brown Box)
Active IngredientAmount
Spinosad 1,620 mg
Product Details
plus minus

What is Comfortis (spinosad)?

Comfortis is the first FDA-approved, chewable beef-flavored tablet (derived from pork protein and hydrolyzed soy) that kills fleas and prevents flea infestations on dogs and cats for a full month. Comfortis for Dogs & Cats requires a prescription from your veterinarian.

For:

Dogs & Cats (14 weeks of age or older)

Benefits:

  • Starts killing fleas within 30 minutes
  • Lasts a full month
  • Kills fleas before they can lay eggs
  • Comes in a convenient chewable, beef-flavored tablet
  • Spinosad, the active ingredient in Comfortis, is environmentally friendly

Comfortis is the #1 recommended Rx Flea-only medication for dogs and cats

How does Comfortis work?

The active ingredient in Comfortis (Spinosad) kills fleas by causing excitation of the insect's nervous system, leading to paralysis and rapid death.

Cautions:

Side effects may occur, including vomiting. If your pet is experiencing loss of appetite, lethargy, or any other difference in behavior, contact your veterinarian. The FDA has received reports of adverse reactions in dogs receiving the drug Comfortis (spinosad) concurrently with high, extra-label doses of ivermectin. Dogs receiving extra-label doses of ivermectin to treat non-responsive demodectic mange and other conditions have developed signs of ivermectin toxicity. Ivermectin is an ingredient found in heartworm preventatives such as Heartgard Plus, Heartgard, Iverhart Plus and Ivomec. In cats, the most common adverse reaction recorded in clinical trials was vomiting. Other adverse reactions were: lethargy, decreased appetite, weight loss, and diarrhea. Use with caution with concomitant extra-label use of ivermectin. For complete safety information, see product label.

Brand Name:

Comfortis (Elanco)

Generic Name:

Spinosad

What is the most important information I should know about Comfortis?

Comfortis is a prescription medication FDA approved for use in dogs and puppies and cats and kittens 14 weeks of age or older to kill fleas and prevent flea infestations for one month. Comfortis is available in a Pink box for dogs 5 to 10 lbs and cats 4.1-6 lbs (140 mg), Orange box for dogs 10.1 to 20 lbs and cats 6.1-12 lbs (270 mg), Green box for dogs 20.1 to 40 lbs and cats 12.1-24 (560 mg), Blue box for dogs 40.1 to 60 lbs (810 mg), and Brown box for dogs 60.1 to 120 lbs (1620 mg). Please note: Cats over 24 lbs should be administered the appropriate combination of tablets.

What should I discuss with my veterinarian before giving Comfortis to my pet?

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

How should Comfortis be given?

Give Comfortis chewable tablets with food. Give Comfortis chewable tablets once a month. Comfortis 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 Comfortis at room temperature (68-77 F)

Comfortis is an easy-to-give oral treatment that doesn't make a mess

What are the potential side effects of Comfortis?

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 Comfortis chewable tablets and talk to your veterinarian if your pet experiences decreased appetite, lethargy or decreased activity, diarrhea, incoordination, weight loss, cough, increased thirst, vocalization, increased appetite, redness of the skin, hyperactivity and excessive salivation. Following concomitant extra-label use of ivermectin with Comfortis, some dogs have experienced the following clinical signs: trembling/twitching, salivation/drooling, seizures, incoordination, excessive dilation of pupils, blindness and disorientation. Post-approval experience continues to support the safety of Comfortis when used concurrently with heartworm preventatives according to label directions.Talk to your veterinarian about any side effect that seems unusual or especially bothersome to the pet.

What happens if I miss giving a dose of Comfortis?

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

What happens if I overdose my pet on Comfortis?

Contact your veterinarian immediately.

What should I avoid while giving Comfortis?

Your pet may maintain normal activities and interactions while being given Comfortis. The safe use of Comfortis in breeding, pregnant, or lactating cats and dogs has not been evaluated.

What other drugs will affect Comfortis?

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

Comfortis is trusted by vets and has been prescribed over 90 million times

See more
How to use
plus minus

Comfortis Directions:

  • Comfortis is a prescription medication used in dogs and cats to kill fleas and prevent flea infestations for 1 month.
  • Comfortis chewable tablets are beef flavored.
  • Comfortis can be given to dogs at least 14 weeks of age, weighing at least 5 lbs, and cats 14 weeks of age, weighing at least 4 lbs.
Tip:

If vomiting occurs within 1 hour of administration, redose the pet with another tablet.

Comfortis Dosage for Dogs:

Dogs/Puppies (14 weeks of age or older):
Weight Dosage
5-10 lbs (Pink Box) Give one 140 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications
10.1-20 lbs (Orange Box) Give one 270 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications
20.1-40 lbs (Green Box) Give one 560 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications
40.1-60 lbs (Blue Box)Give one 810 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications
60.1-120 lbs (Brown Box)Give one 1620 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications
Over 120 lbs Give the appropriate combination of tablets

Comfortis Dosage for Cats:

Cats/Kittens (14 weeks of age or older):
Weight Dosage
4.1-6 lbs (Pink Box) Give one 140 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications
6.1-12 lbs (Orange Box) Give one 270 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications
12.1-24 lbs (Green Box) Give one 560 mg chewable tablet by mouth once a month. Comfortis may be chewed, offered in food, or administered like other tablet medications
Over 24 lbs Give the appropriate combination of tablets
Comfortis Dosage for Horses:
Horses
Do not use!
Storage:

Store Comfortis at room temperature (68°-77° F).

Ingredients
plus minus

Comfortis Ingredients:

Comfortis for Dogs: 5-10 lbs - Comfortis for Cats: 4.1-6 lbs (Pink Box)
Active IngredientAmount
Spinosad 140 mg
Comfortis for Dogs 10.1-20 lbs - Comfortis for Cats: 6.1-12 lbs (Orange Box)
Active IngredientAmount
Spinosad 270 mg
Comfortis for Dogs 20.1-40 lbs - Comfortis for Cats: 12.1-24 lbs (Green Box)
Active IngredientAmount
Spinosad 560 mg
Comfortis for Dogs 40.1-60 lbs (Blue Box)
Active IngredientAmount
Spinosad 810 mg
Comfortis for Dogs 60.1-120 lbs (Brown Box)
Active IngredientAmount
Spinosad 1,620 mg
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PMSF
2 months ago
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Breed Mixed
Large pill
A follow up to my earlier review under PMSF. I've attached a photo showing the pill size compared to a Greenies cat pill pocket.
Review photo Review photo
Helpful?
SailorLady
3 months ago
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Breed Tibetan Terrier
Solved the flea problem!
BJ, our Tibetan Terrier, kept scratching at his hind leg, leaving a red, hairless spot. He was on Frontline Plus. Took him to the vet, where a dead flea dropped off while he was on the table! Vet said some dogs are super sensitive to flea bites, and fleas can live up to 24 hours after biting a dog with Frontline. Switched to Comfortis. Hair grew back, scratching stopped. Happy dog, happy owner!
Helpful?
PMSF
6 months ago
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Breed Mix
Large pill
This pill is way too large for any cat to swallow. My cat is part main coon and 12.2lbs so vet recommended the dosage within that weight range. I have no idea if the pill sizes are different for the various dosage sizes. The pill can be cut with a knife and will leave some crumbles. The pill needs to be divided into 8 pieces (at least) to fit inside a cat-sized pill pocket. My cat doesn't like the smell and won't eat it if it's not masked by the pill pocket. Because it's challenging to mask these larger pieces with the pill pocket, it's been difficult to get him to eat all the pill pockets (which he LOVES). Personally, I would prefer a much smaller pill that will fit inside a cat-sized pill pocket and can be administered over a few days (so he's not eating so many pill pockets at once). I'm trying this because my cat developed a reaction to Revolution Plus (after many years of use) so the vet recommended an oral application.
Helpful?
Nipper
7 months ago
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Breed Mix
Fleas are gone
Gave it to them and not even three days later fleas were gone. Worst thing is they hate the smell and will not chew it, so I had to make them swallow it, but that a side I'm very satisfied.
Helpful?
Tazie
8 months ago
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Breed Pomeranian
Small price to pay for relief for my baby.
Our baby has been on Comfortis for about 5 years now or more. It has been the best since starting. We treat our yard also so during the fall and winter months we let her be free of meds. It always jump right back into fear once starting her back up in spring. By far the BEST, prevention after trying many.
Helpful?
Kat1
11 months ago
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Breed Yorkie-poo
Works Great!!
My yorkie-poo became allergic to flea debris. I was using a topical flea medication, and needed to switch to one in pill form. Luna has a sensitive stomach, so her vet suggested Comfortis. I couldn't be happier with the results.
Helpful?
MHPCA
1 year ago
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Breed Long hair mix
Works great
My kitty really likes this and grinding it up and putting in her food wasn’t a problem.
Helpful?
puglover555
1 year ago
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Breed pug
works better than anything else.
I've had dogs for 45 years. To keep them healthy, I have always tried to keep the fleas off of them. I have tried SO many things. Topicals used to be my 'go to'. But over the years, fleas seem to have adapted and become resistant to a lot of medicines and chemicals. The topical drops I used for years hardly do anything at all now; money down the drain. It's not really good to bath your dog often, either. It can strip the natural oils from the skin, and, over time, cause skin issues and irritations. The last topical I tried for my pug, (it was from the vet's office, and expensive!) gave my dog an actual chemical burn! He was so upset and sickly for almost an entire week, I felt terrible. BAD Mommy! I've also tried other chewables, and they made my dog's stomach very unhappy for a couple days. I've tried sprays, which are so terribly offensive to your poor babies; with their sense of smell, it is akin to torture! And dangerous, because it can get in their eyes, or they can lick it. Comfortis isn't cheap. But if you are like me, and your animals are your children, this stuff is effective and safe. (Of course there's always the odd allergic pet, but I've never had any issues). I have picky dogs. They really don't like the taste of this...(smell it yourself, It's gross.) so I break it up into smaller pieces that can be hidden inside pieces of meat or cheese. Occasionally they discover my covertness, and spit out the piece, then look at me like, "Really Mom?.Seriously?!?" Heh...heh... I just switch treats or, wait a little while and try again. (Personally, I'd like to see the pills very tiny, with a coating that seals-in the taste and scent. You may have to give several pills, but it would be much easier to sneak it into their treats or food.) Of course, there is always the dog that eats anything you give them, and has no troubles with eating this chewable right up; just not my fussy, little brats! You can certainly crush it up, and mix it with their food, but for me, this was an expensive, failed experiment. Once they decide NOT to eat it, you've wasted a pill, and that can get costly. But it WORKS. And no skin irritation, or stomach troubles. Like I said, it's the best I have found. Good luck!
Helpful?
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