Indoxacarb (Activyl® Spot-On) for Dogs and Cats

Overview of Using Indoxacarb (Activyl®) Spot-On for Dogs and Cats

  • Activyl® is a spot-on (topical) flea treatment for dogs and cats. The active ingredient is indoxacarb.
  • Indoxacarb is an antiparasitic agent primarily used to kill adult fleas.
    Activyl® features bioactivation, a mechanism of action that uses enzymes in the flea to activate the ingredients to kill the fleas. According to the manufacturer, “ the indoxacarb in Activyl® is bioactivated in the flea by enzymatic N-decarbomethoxylation changing it to a more active, highly insecticidal metabolite.” In mammals indoxacarb is a harmless ingredient.
  • Activyl works by interfering with the brain and spinal cord of susceptible insects, resulting in death.
  • Activyl is a topical solution that collects lipid layter of the skin and spreads throughout the coat. It is not absorbed into the body and does not circulate through the blood stream.
  • The effects of Activyl® lasts about 30 days and remains effective after swimming or bathing.
  • Activyl contains 19.53% Indoxacarb: (S)-methyl 7-chloro-2,5-dihydro-2-[[(methoxycarbonyl)[4-trifluoromethoxy)phenyl]amino]-carbonyl]indeno[1,2-e][1,3,4]oxadiazine-4a(3H)-carboxylate.
  • Activyl® begins killing fleas within 8 hours.
  • Activyl® is a presciption flea and tick products and can not be obtained without a veterinary prescription.

Brand Names and Other Names

  • This drug is registered for use in animals only.
  • Human formulations: None
  • Veterinary formulations: Activyl ® (Merck)

Uses of Activyl® for Dogs and Cats

  • Activyl® is used in the control and treatment of immunature flea forms including eggs and larvae as well as adult flea in dogs, puppies, cats and kittens. For more information on flea infestations, please see Flea Infestation in Cats or Flea Infestation in Dogs.

Precautions and Side Effects with Activyl®

  • While generally safe and effective when prescribed by a veterinarian, Activyl® can cause side effects in some animals.
  • Activyl® should not be used in animals with known hypersensitivity or allergy to the drug.
  • Activyl® is not recommended for use in kittens less than 2 pounds or under 8 weeks of age or in dogs under 4 pounds of body weight or under 8 weeks of age.
    Not recommended for pregnant or lactating cats or dogs.
  • Activyl® may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with Activyl®.
  • Activyl® is a topical agent and temporary irritation at the site of application is possible.
  • Activyl is fast drying, however spotted areas may appear wet or oily for up to 24 hours.
  • Overdose is rare. Oral ingestion (a cat that licks Activyl) may cause drooling, licking, vomiting, shaking of the head, and squinting in some pets.

How Activyl® is Supplied

  • Activyl® is available in two sizes for cats and 5 sizes for dogs. Activyl® is packaged in single units as well as 6 packs.
  • For cats, “Activyl® Spot-On for Cats” comes in a topical solution available which contains 0.03 fl.oz. (1.03 mL) for cats over 9 lb and 8 week of age and older. “Activyl® Spot-On for cats and kittens” contains 0.02 fl.oz. (0.51 mL) for Cats and Kittens 2 to 9 lb and over 8 weeks of age.
  • For dogs, Activyl comes in the following sizes.

    • Activyl® Spot-on for Dogs and Puppies (over 4 pounds (lbs) and up to 14 lbs)
    • Activyl® Spot-on for Dogs and Puppies (over 14 lbs and up to 22 lbs)
    • Activyl® Spot-on for Dogs and Puppies (over 22 lbs and up to 44 lbs)
    • Activyl® Spot-on for Dogs and Puppies (over 44 lbs and up to 88 lbs)
    • Activyl® Spot-on for Dogs and Puppies (over 88 lbs and up to 132 lbs)
  • Fragrance free.

Dosing Information on Activyl® for Dogs and Cats

  • Medication should never be administered without first consulting your veterinarian.
  • Activyl® is supplied in two sizes for cats and 5 sizes for dogs as listed above. It is approved for cats over 2 pounds, puppies over 4 pounds and both puppies and kittesn over 8 weeks of age.
  • One pipette is applied topically every 30 days.
  • The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects.