Efficacy of daily amitraz on generalised demodicosis in dogs.

Fifty dogs with generalised demodicosis were treated with daily applications of 0.125 per cent amitraz solution over half the body. This was applied once a day, alternating the body half treated. Nine dogs were lost to follow-up; the remaining dogs were classified as either a success (25 dogs, 61 per cent) or a failure (16 dogs, 39 per cent) according to their response to treatment. Eight of the failures were due to persistent demodicosis and eight relapsed within one year after treatment. All eight of the relapsed dogs were cured after a second course of daily amitraz treatment. For the 25 dogs considered treatment successes, the median duration of treatment was 6.5 weeks (range, three weeks to nine months), and the median interval from completion of treatment to last post treatment evaluation was 3.4 years (range, two to four-and-a-half-years). Including the eight dogs that were cured after retreatment, the daily amitraz applications were curative in 33 of 41 dogs (80 per cent) with generalised demodicosis.