Field efficacy of a 10 per cent pyriproxyfen spot-on for the prevention offlea infestations on cats

The clinical application of a new method for using the insect growth regula tor, pyriproxyfen, for controlling flea populations in cat-owning homes is evaluated for the first time. In a multicentric, controlled and randomised trial, 107 flea-infested cats were treated with a minimum dose of 10 mg/kg bodyweight pyriproxyfen as a 10 per cent spot-on application on two occasio ns, with a three-month interval between doses. For comparison, 99 cats rece ived lufenuron suspension orally, once a month, for six months. Flea counts decreased significantly over time in each group and were significantly low er in the pyriproxyfen group than in cats treated with the reference produc t. The percentage of 'zero-flea' cats increased from 49 per cent on day 30 to 88 per cent on day 180 in the pyriproxyfen group and from 30 to 71 per c ent in the lufenuron group at the same time points (P < 0.05). Appropriatel y timed topical applications of pyriproxyfen, therefore, offer a method of flea control in the domestic environment.