Comfortis Chewable Tablet for Dogs, 20.1-40 lbs & Cats 12.1-24 lbs, (Green Box), 6 Chewable Tablets (6-mos. supply)
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Comfortis is a chewable medication prescribed by veterinarians for dogs and cats to help treat -- and possibly even prevent -- flea infestations for up to one month. These flavored tablets can be added to your pet's favorite food and only need to be given to your canine companion once a month to help combat fleas.We directly source prescription medications from manufacturers and wholesale distributors registered with the FDA and licensed by applicable state boards. Guaranteed genuine, and where applicable, backed by the manufacturer.
Ingredients
560 mg Spinosad.
Instructions
Dose varies based on pet's weight. Use according to your veterinarian's instructions. Comfortis is generally given once a month, but you should always follow your veterinarian's directions. It is recommended to give Comfortis chewable tablets with food.
Store at temperatures between 68° - 77°F.
FAQ
They’re beef-flavored, chewable tablets you give to your dog or cat to kill fleas and prevent flea infestations for one month. Comfortis chewable tablets are recommended for monthly use in cats 14 weeks of age or older and 4.1 lbs of body weight or greater and in dogs 14 weeks of age or older and 5 lbs of body weight or greater.
Spinosad is the active ingredient in Comfortis. It belongs to a class of antiparasitics known as spinosyns, which are derived from a naturally-occurring soil microbe. It works by attacking the nervous system of insects, causing the rapid death of adult fleas.
Treatment can begin at any time of the year. Comfortis is most effective when given one month before fleas become active, with continued monthly dosing through the end of the flea season. In areas where fleas are common year-round, monthly treatment with Comfortis chewable tablets should continue through the entire year without interruption. To minimize the likelihood of flea re-infestation, simultaneously treat all animals in your household with an approved flea protection product. Consult your veterinarian for the flea treatment options most appropriate for your area. See also, what should I discuss with my veterinarian regarding Comfortis for my dog or cat?
Spinosad, the active ingredient in Comfortis, began killing fleas in 30 minutes and killed 100% of fleas on dogs and 98% of fleas on cats in just four hours in controlled laboratory studies. Comfortis chewable tablets kill fleas before they can lay eggs.
Comfortis has demonstrated full effectiveness for an entire month.
Comfortis kills fleas before they can lay eggs when used monthly, according to the label directions. If you see fleas on your dog or cat within a month after your pet receives Comfortis, they are most likely new fleas. Because your pet has been treated with Comfortis, these new fleas will be killed before they can produce eggs that contaminate your home. Continued monthly use of Comfortis can prevent any new flea infestations.
Your pet can experience continued exposure to fleas living in the environment. It’s important to treat all animals in the household with an approved flea product to help control the flea population. Learn more about controlling flea infestations in your home.
Comfortis has demonstrated to be safe in healthy dogs and cats when used according to label directions. Use only for cats and kittens 14 weeks of age or older and 4.1 lbs of body weight or greater, and for dogs and puppies 14 weeks of age and older and 5.0 lbs of body weight or greater. The safe use of Comfortis in breeding, pregnant or lactating cats and dogs has not been evaluated.
Comfortis contains beef flavoring made from a pork-based protein. If your pet has an allergy to pork, you may need to consider an alternative for flea treatment and prevention. Please discuss these options with your pet's veterinarian. The use of ivermectin at higher than FDA-approved doses at the same time as Comfortis can result in serious side effects.
As with any medication, sometimes side effects occur. See the Comfortis label for complete safety information.
For cats: The following adverse events reported for cats are listed in decreasing order of reporting frequency: Vomiting, depression/lethargy, anorexia, behavioral changes, pruritus, diarrhea, ataxia, hyperactivity, hypersalivation, panting, vocalization, dyspnea, twitching, and seizures. In some cases, death has been reported. Some of these reports involved cats with cardiac disease, including cats with previously undiagnosed cardiac disease. Following concomitant extra-label use of ivermectin with COMFORTIS, some cats have experienced the following clinical signs: ataxia, trembling/twitching, seizures, mydriasis, disorientation, and transient blindness.
For dogs: The following adverse events reported for dogs are listed in decreasing order of reporting frequency: Vomiting, depression/lethargy, pruritus, anorexia, diarrhea, seizures, ataxia, trembling, behavioral changes, and hypersalivation. Following concomitant extra-label use of ivermectin with COMFORTIS, some dogs have experienced the following clinical signs: Trembling/twitching, salivation/drooling, seizures, ataxia, mydriasis, blindness, and disorientation.
Administer Comfortis with food for maximum effectiveness. Because Comfortis is a flavored tablet, it can be offered just prior to or just after feeding. You can also administer Comfortis as you would other tablet medications. Visit the Dosing & Administration page for more details, or download the Comfortis label. Each box includes reminder stickers for your calendar to help remind you to administer each dose. You can also sign up for monthly text or email reminders.
In field trials, dog and cat owners were instructed to give the Comfortis tablet with food. However, the quantity of food was not specified and Comfortis was still effective. An option is to give Comfortis immediately before a regularly scheduled meal. For free feeders (dogs or cats who nibble throughout the day), you might take food away at night, administer Comfortis first thing in the morning, then put the food back down.
Give your pet his or her regular dose immediately, then resume a regular monthly schedule. To help you remember to dose your pet, sign up for monthly email or text message reminders. For complete safety information, view the Comfortis label.
Contact your veterinarian if you believe your pet has ingested more than the recommended dose of Comfortis. Visit the Dosing & Administration page for more details, or see the Comfortis label for complete safety information.
No. You can continue normal activities and interactions with your pet.
Comfortis is not contraindicated for use with any veterinary drug/product when they are administered at labeled doses. However, while labeled heartworm preventatives are not an issue, you should not use Comfortis concurrently with extra-label doses of ivermectin in dogs and should use caution in cats. Make sure your veterinarian is aware of all products that you intend to administer to your pet. In well-controlled field studies, Comfortis chewable tablets were administered safely in conjunction with other frequently used labeled products, such as vaccines, anthelmintics, antiparasitics, antibiotics, steroids, tick control products, anesthetics, NSAIDs, antihistamines, alternative/herbal remedies, shampoos, prescription diets, and most generally prescribed medications.
Your veterinarian is your pet's healthcare expert and can make the best medication recommendations. This includes the prevention, control and/or treatment of parasites such as fleas, heartworms and intestinal parasites. These parasites can cause conditions including flea allergy dermatitis, anemia, and heart disease. Key points of your discussion might include:
- The best time to start flea treatment in your geographic region.
- What administration method will work best for your pet.
- What to do if you miss a dose of Comfortis.
- What other medications you give your pet.
- What to do about a severe flea infestation.
- What steps you can take to prevent a flea re-infestation in your home.

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Customers Mention
Ease of Use
Effectiveness
Ingredients
Long-Term Benefits
147 Customer Reviews
Flea killer
This is the first time This product has NOT worked! $125 and fleas are still everywhere on both my cats! It's so bad I had to spend almost $100 to take Chance to
This is the first time This product has NOT worked! $125 and fleas are still everywhere on both my cats! It's so bad I had to spend almost $100 to take Chance to the vet because he wouldn't come out from under the bed, it's so bad that I just spent another $101+ for Nexguard Combo. I've had to spend $296 including the Comfortis on killing fleas! I'm so upset especially because I am disabled and elderly and only get $900 and change from Social Security! The vet still wants to do bloodwork on both my cats at $150 each cat! What happened? I've used this for years and never had a flea on either cat...
Flea prevention for my Yorkies
Comfortis always does the trick to get rid of the fleas on two Yorkies and seems to do well with their sensitive stomachs. My girl does not like the taste and I
Comfortis always does the trick to get rid of the fleas on two Yorkies and seems to do well with their sensitive stomachs. My girl does not like the taste and I have to force her to take the pill but Comfortis works very well!
Probably a good product...just not for my cat
Gave this to my cat with food and he immediately threw up, then avoided eating his food for two days afterward. Nothing wrong with Chewy and the product probably
Gave this to my cat with food and he immediately threw up, then avoided eating his food for two days afterward. Nothing wrong with Chewy and the product probably works, just didn't agree with my cat.
Didn't work
Been a couple of weeks and still seeing fleas in the house and on my dog. Don't waste your money
Been a couple of weeks and still seeing fleas in the house and on my dog. Don't waste your money
SO frustrating!
My cats would not take these hard pills even after I ground them to powder and mixed with wet food. The smell is horrible - the smell overtook the food. I had
My cats would not take these hard pills even after I ground them to powder and mixed with wet food. The smell is horrible - the smell overtook the food. I had to get two different boxes for the correct weight dosage, so I basically threw away about $270.00. I would rate it a negative number if I could.
Love that this has minimal medicine but...
Specifically us e this bc it is monthly (as opposed to every 12 weeks so lower does) and is fleas only (no anti0tick) as I try to give my god the minimal amount
Specifically us e this bc it is monthly (as opposed to every 12 weeks so lower does) and is fleas only (no anti0tick) as I try to give my god the minimal amount of medication possible but... my dog hates the taste. Literally spits it out even if hidden in food.
Flea Chewable Meds
These tablets are convenient and do work well to prevent and maintain flea control. My dogs do not like the tablets and it is difficult to get them to eat the food
These tablets are convenient and do work well to prevent and maintain flea control. My dogs do not like the tablets and it is difficult to get them to eat the food we mix with it.
Timely delivery
Easily orders and timely delivery make Chewy desirable. I just wish the stuff was less expensive, but that is not their fault.
Easily orders and timely delivery make Chewy desirable. I just wish the stuff was less expensive, but that is not their fault.
Kill fleas
This is the best product I have been using for so many years and I never had a problems with my pets
This is the best product I have been using for so many years and I never had a problems with my pets
The method of applying it on the animal. Highly recommended by our vet!
Comfortis is crushed into a powder, easily taken in by the animal when mixed over their dry or wet food.
Comfortis is crushed into a powder, easily taken in by the animal when mixed over their dry or wet food.