Why Can't I Put Dog Flea Medication on My Cat?

Cats and dogs have different sensitivities to medicine. As a result, veterinarians formulate different medications separately for not only dogs and cats, but different types and sizes of dog and cat.

  1. Active Ingredient

    • Permethrin, the active ingredient in dog flea medication, acts as a poison for cats as well as fleas.

    Metabolism

    • The metabolism of dogs break down permethrin differently than cats, allowing dogs to pass the synthetic insecticide through their urine. The metabolism of a cat cannot break down permethrin and it can quickly build to toxic levels.

    Symptoms

    • Cats experiencing poisoning by permethrin may drool abnormally, vomit, or show signs of fatigue, muscle tremors, or even seizures.

    What to do

    • Permethrin toxicity can lead to death. Seek veterinary treatment immediately if you suspect a cat may have been treated with flea medication intended for dogs.

    Treatment

    • Veterinarians treat cats suffering from permethrin poisoning by thoroughly bathing the cat to remove all traces of flea medication. Fluids and medications to control seizures may also be used. Muscle tremors can last for several days, but most cats under veterinary care recover within a few days.