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Comfortis by Elanco

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Comfortis® Chewable Tablets

Comfortis's Generic Name:


Comfortis General Description:

A fast acting, beef-flavored chewable tablet to give your dog or cat month long flea protection. Spinosad starts to kill fleas within 30 minutes of application, and eliminates 100% of your dog's or cat's fleas within 4 hours. Safe for use in dogs and cats older than 14 weeks. The active ingredient, spinosad, is environmentally friendly and FDA approved. Packages are available in five sizes, each containing a six month supply.

What is Comfortis Chewable Tablets?
  • A biologic product, an ultra-fast flea-killing tablet
  • Classified by the USDA as an organic substance (considered a drug, not an insecticide)
  • Given by mouth
Reasons for prescribing flea protection:
  • For the prevention and treatment of flea infestation on the dog
  • Prevents future infestations when used monthly
  • Does not kill other internal or external parasites
What dogs/cats should not take Comfortis Chewable Tablets?


  • Use with caution in dogs with pre-existing epilepsy
  • Dogs less than 14 weeks of age
  • Use with caution in breeding, pregnant or nursing dogs
  • The safe use of spinosad in male breeding dogs has not been established
  • If your pet has had an allergic reaction to spinosad or like products

Give with food monthly for maximum effectiveness.

Treatment may begin at any time of the year. Ideally, begin administration one month before fleas become active, and then continue monthly throughout flea season. Should your area experience fleas year-round, give spinosad monthly without interruption.

To minimize re-infestation, treat all pets in the house with an approved product.

You can play with your dog immediately after treatment. There is no need to isolate your pet.

Read and follow the label carefully.

What if a dose is missed?

If a dose is missed, give it as soon as you can and resume a monthly dosing schedule. Do not give two doses at the same time.

What to tell/ask veterinarian before giving Comfortis Chewable Tablets?

Talk to your veterinarian about:

  • When will your pet need to be rechecked
  • What tests may need to be performed prior to and during treatment with this drug
  • What are the risks and benefits of using this drug

Tell your veterinarian about:

  • If your pet has experienced side-effects on other drugs/products
  • If your pet has experienced any other medical problems or allergies now or ever
  • All medicines and supplements that you are giving your pet or plan to give your pet, including those you can get without a prescription. Your veterinarian may want to check that all of your pet's medicines can be given together.
  • If your pet is pregnant or nursing or if you plan to breed your pet
Comfortis Storage and Warnings:
  • Store at 20-25°C (68-77°F), excursions permitted between 15-30°C (59-86°F).
  • Keep this and all medication out of reach of children and pets. Not for human use.
  • Call your physician immediately if you accidentally take this product.
Potential side effects of Comfortis Chewable Tablets:
  • The most common adverse reaction is vomiting. If your dog vomits within 1 hour of administration, re-dose with another full dose
  • Other side effects include decreased or increased appetite, lethargy, diarrhea, cough, increased thirst, vocalization, redness of the skin, hyperactivity and drooling.
  • Synthetic beef flavor is actually derived from pork protein and hydrolyzed soy. Use with caution in dogs allergic to pork.
  • If these symptoms persist or you notice anything else unusual, contact your veterinarian
Can this drug be given with other drugs?
  • Yes, but possible interactions may occur with high doses of ivermectin
  • If your pet experiences any unusual reactions when taking multiple medications, contact your veterinarian

Contact your veterinarian immediately if pet eats more than the prescribed amount.

What else should I know about Comfortis Chewable Tablets?

Notify your veterinarian if your animal's condition does not improve or worsens despite this treatment.

As with all prescribed medicines, spinosad should only be given to the pet for which it was prescribed. It should be given only for the condition for which it was prescribed.

This is just a summary of information about spinosad. If you have any questions or concerns about spinosad or the condition it was prescribed for, contact your veterinarian.


Common Drug Name

Common Brand Names
Generic products are not available.

Store at room temperature.

Spinosad is used to kill fleas and is indicated for the prevention and treatment of flea infestations.

Dose and Administration
Always follow the dosage instructions provided by your veterinarian. If you have difficulty giving the medication, contact your veterinarian.
Give by mouth once a month.  Spinosad should be given with food for maximum effectiveness.
If vomiting occurs within one hour of administration, redose with another full dose.
If you miss a dose, give it as soon as you remember and resume giving spinosad every 30 days (once a month).
Spinosad is preferably started one month before fleas become active and should be given monthly through the end of the flea season.  In areas where fleas are common year-round, monthly treatment should continue the entire year without interruption.
To minimize the likelihood of flea reinfestation, it is important to treat all animals within a household and the environment with approved flea control products.
This medication should only be given to the pet for whom it was prescribed.

Possible Side Effects
Side effects are rare at the recommended dosage.  May see vomiting, decreased appetite, lethargy, diarrhea, cough, excessive thirst, vocalization, increased appetite, redness of skin, hyperactivity or excessive salivation.   Consult your veterinarian if you notice any of the above side effects.
If your pet experiences an allergic reaction to the medication, signs may include facial swelling, hives, scratching, sudden onset of diarrhea, vomiting, shock, seizures, pale gums, cold limbs, or coma. If you observe any of these signs, contact your veterinarian immediately.

Not for use in animals hypersensitive (allergic) to spinosad.
Use with caution in breeding, pregnant or lactating animals (female animals nursing their young). Spinosad enters the mother’s milk. Consult your veterinarian before using spinosad in a lactating dog.
The safe use of spinosad in breeding male dogs has not been evaluated.
Do not use in dogs less than 14 weeks of age.
Use with caution in dogs with pre-existing epilepsy.
Consult with your veterinarian regarding the physical examinations and laboratory testing necessary prior to and during treatment with spinosad.

Drug, Food and Test Interactions
Notify your veterinarian of any other medications, including vitamins and supplements your pet is taking while your pet is receiving spinosad.
Do not use spinosad in animals that are receiving high doses of ivermectin (above the usual heartworm prevention dose), as ivermectin toxicity may occur.

Signs of Toxicity/Overdose
Rare. May see any of the side effects listed. If you know or suspect your pet has had an overdose, or if you observe any of these signs in your pet, contact your veterinarian immediately.
Keep this and all other medications out of the reach of children and pets.

This information may not cover all possible uses, directions, side effects, precautions, allergic reactions, drug interactions, or withdrawal times.  Always consult your own veterinarian for specific advice concerning the treatment of your pet.

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