Use of Fipronil to treat ear mites in cats

A colony of cats (n=15) with a history of chronic ear mite infection was treated with topical fipronil (100g/L). When 0.05mL was applied to the skin at the opening of each ear canal and 0.4mL, applied between the shoulder blades, eight our, of 12 cats which tested positive for Otodectes cynotis at the commencement of the trial were negative 35 days later. Two other cats remained negative throughout the trial and one cat which was negative at the commencement of the trial became infected during the 35 days after treatment, 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 infected at the commencement of the trial tested negative seven days after treatment 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 were seen in any animals, Application of topical fipronil directly into the ear canal offers promise as a means of treating O. cynotis infection in the cat