Use of fipronil to treat ear mites in cats

A colony of cats (n=15) with a history of chronic ear mite infection was tr eated with topical fipronil (100g/L). When 0.05mL was applied to the skin a t the opening of each ear canal and 0.4mL, applied between the shoulder bla des, eight our, of 12 cats which tested positive for Otodectes cynotis at t he commencement of the trial were negative 35 days later. Two other cats re mained negative throughout the trial and one cat which was negative at the commencement of the trial became infected during the 35 days after treatmen t, In a second study, when 0.05mL of fipronil was placed directly into each ear canal and 0.4mL applied between the shoulder blades, all 10 cats infec ted at the commencement of the trial tested negative seven days after treat ment and remained negative on days 14, 21 and 28 following treatment. None of the dye cats which were negative at the commencement of the second trial became infected during the 28 day monitoring period. No adverse effects we re seen in any animals, Application of topical fipronil directly into the e ar canal offers promise as a means of treating O. cynotis infection in the cat.