Читать книгу Canine and Feline Epilepsy - Luisa De Risio - Страница 117

Pyrethrins are natural insecticides obtained from Chrysanthemum cinerariaefolium, while pyrethroids (e.g. permethrin and fenvalerate) are synthetic analogues of pyrethrins classified as type I (no alpha-cyano-3-phenoxybenzyl group) or type II (with alpha-cyano-3-phenoxybenzyl group) (Hansen, 2006; Wismer and Means, 2012). Etofenprox is a nonester pyrethroid-like insecticide. Permethrin toxicosis is one of the most commonly reported poisonings in the USA and the UK in small animals. Pyrethrins and pyrethroids can be absorbed dermally, orally (e.g. grooming in cats) and via inhalation. Many pyrethrin and pyrethroid formulations are registered for topical use on dogs and/or cats (as spot-on, flea collars, medicated shampoo) and in the household for flea and tick control. Generally, most products registered for use on dogs and cats are safe when used according to label directions in healthy pets. Cats are more sensitive than most other species to pyrethrins and pyrethroids probably due to deficiencies in glucoronyl transferase resulting in slower hepatic metabolism of these compounds. Intoxication results from administration to cats of products labelled for use on dogs, overdose or repeated over-application (Hansen, 2006). Secondary exposure may occur in cats that are in contact with dogs or treated environments. Pyrethrins and pyrethroids are highly lipophilic and rapidly distribute to adipose tissue and the central and peripheral nervous system (Wismer and Means, 2012).