Several products containing essential oils are sold as flea and tick preventives. Certain plant-derived natural flea products, considered minimum-risk pesticides, are exempt from EPA regulations and could cause significant adverse events in dogs and cats. This report described adverse reactions in 39 cats and 9 dogs from a retrospective review of cases from the Animal Poison Control Center (APCC) database from 2006 to 2008. Of these, 44 showed 1 or more adverse events associated with exposure (eg, behavioral changes; CNS, GI, respiratory effects). Four cases did not develop signs, but the APCC was contacted because of inappropriate product use or multiple cohabitating animals were exposed but only 1 showed signs. The products were usually (77%) applied per label directions. Signs were reported in 10/11 animals when the product was used inappropriately. Final outcome was known in 28 of the patients: 21 fully recovered, 4 did not show signs, 1 cat died, and 1 dog and 1 cat were euthanized. There is a growing availability of natural pet products and some owners believe natural products are safer than synthetic products. Owners should be aware that plant-derived ingredients are not without risk and evidence regarding efficacy of these products is lacking.

Many owners think they have their pet’s best interest in mind when providing natural ingredients. However, natural does not equate to safety, as these products do not have regulatory oversight or established mechanisms to collect or report adverse events. Practitioners should advise clients about the best choices for ectoparasite control and encourage them to follow directions closely, regardless of the product used. Practitioners likewise need to listen to clients’ concerns about recommended products.—Patricia Thomblison, DVM, MS

Adverse reactions from essential oil-containing natural flea products exempted from Environmental Protection Agency regulations in dogs and cats. Genovese AG, McLean MK, Khan SA. JVECC 22:470-475, 2012.