ASPCA NATIONAL ANIMAL POISON CONTROL CENTER
1717 S. Philo Road, Suite 36
Urbana, IL 61802
PERMETHRIN HAZARDS FOR CATS
Fleas are a major problem for cat owners. Not only are these tiny creatures a nuisance, they are also the cause of many diseases such as flea anemia, flea bite dermatitis, and tapeworm infestation. Therefore, flea control is often a necessary step in maintaining your cat's health.
Cat owners should always follow label instructions when using flea products. For instance, flea products that are labeled "for use on dogs only" should never be used on cats. Cats react very differently than dogs to some insecticides and some products that are safely used on dogs can be deadly to cats, even in small amounts.
An example of such a species difference is permethrin sensitivity in cats. There are many permethrin spot-on products available that are labeled for "dogs only." These contain high concentrations (45-60%) of permethrin insecticide. These permethrin products have a good range of safety when used on dogs, but even a few drops of concentrated permethrin could be lethal to a cat. Cats are most commonly exposed to these products through inappropriate application by their owners. The signs commonly seen with permethrin toxicity in cats include generalized tremors, muscle fasciculations, and seizures. Signs can develop within hours or may be delayed up to 48 hours.
Though most cats will recover with appropriate treatment by a veterinarian, the best way to avoid serious problems is by using products strictly according to their label directions. Never use products labeled for "dogs only on your cats." Before using ANY product on your cat, read the label instructions completely. If you do not completely understand the instructions, you should contact the product manufacturer or your veterinary staff for clarification. Remember, reading the label could save the life of your cat!
Jill A. Richardson, DVM
Veterinary Poison Control Center
ASPCA National Animal Poison Control Center
March 1, 2000