This study was a retrospective review of 42 cases of feline permethrin toxicity treated at a referral hospital in Australia. Most of the cases had a canine permethrin spot-on (PSO) flea product directly applied to the affected cats. Approximately half of the cases developed toxicity following a PSO product purchased from a supermarket. Most of the cases occurred in the summer. Cats are particularly sensitive to the effects of permethrin. Tremors and muscle fasciculations were the most common clinical sign exhibited in 86% of cats affected followed by twitches, hyperesthesia, seizures, pyrexia, ptyalism, ataxia, mydriasis, and temporary blindness. The clinical onset of signs was from a few hours up to 24-72 hours after application of the PSO. There was no correlation between the amount of permethrin applied and the severity of clinical signs induced. In this study, treatment involved decontamination, anticonvulsants, and supportive care. Methocarbamol was not used. Hypothermia was the most common complication found during treatment, followed by electrolyte abnormalities. One cat had to be euthanized during treatment. Results of this study suggest that the lack of availability of methocarbamol for treatment should not preclude treatment of permethrin toxicity. [VT]
Sutton NM, Bates N, Campbell A: Clinical effects and outcome of feline permethrin spot-on poisonings reported to the Veterinary Poisons Information Service (VPIS), London, J Feline Med Surg 9:335, 2007.