ISFM Protect Against Permethrin Poisoning Campaign

As advocates for cats, and their health and wellbeing, the American Association of Feline Practitioners is taking a leading role in informing the US public, pet guardians as well as the veterinary professional about the dangers of the inappropriate use of products containing permethrins. As such, the AAFP has endorsed the ISFM's Protect Against Permethrin Poisoning Campaign to educate and advocate for more visible warnings on permethrin containing products with the goal of decreasing or even eliminating a major cause of feline toxicity.

The topical application to cats of flea control products marketed for dogs containing permethrins constitutes a major portion of feline toxicities reported to the ASPCA Animal Poison Control Center. These incidents generally occur as either deliberate application of the product by an owner unaware of the dangers, or by the indirect exposure of cats to those products via such things as grooming of dogs on whom these products have recently been applied.

Toxicity occurs as a result of an insufficient glucuronide conjugation of the permethrin by the feline liver, resulting in high levels of the permethrin. This is further complicated by the fact that canine marketed permethrin products typically contain 45-60% permethrin while safe feline marketed products contain less than 0.1%. These products are absorbed through the skin and tend to concentrate in nervous tissue, resulting in signs ranging from restlessness and hypersalivation, to muscle spasms, seizures, and death.

Pet owners should be extremely careful when applying any permethrin containing products either on pets, or within the pet's environment. Owners should follow label instruction to avoid putting dog strength product on cats, or allowing cats to come in contact with dogs who have recently had permethrin products applied. Environmental pest control practices using pyrethrin products must also be used cautiously if cats are to be in that environment.

Veterinary practices in the United States should be aware of the clinical signs of permethrin poisoning. It must be included in the differential for any cats presented for hypersalivation, anxiousness, muscle tremors, or seizures. Careful questioning of owners concerning recent animal or environmental pest control may be necessary to determine likelihood of exposure. Prompt treatment of such cases is necessary for the cat's survival. Treatment may include intravenous or intra-rectal methocarbamol and seizures may be controlled with barbiturates, propofol or inhalant anesthetics. Diazepam is not as effective in controlling the seizures as the above medications.

As owners obtain flea control products from sources other than veterinary practices, that is big box stores, human pharmacies, pet stores and the Internet, there may be less counseling as to proper use of these chemicals. In addition, warnings on labels may not adequately relate the toxic potential of the product to the pet owner, resulting in the application of inappropriate products to cats.

Submitted by: Gerry Beekman, D.V.M.