Abstract
Cows with dermatological lesions and pruritus caused by naturally occurring infestation with Chorioptes texanus were observed in a tie-stall dairy farm in Kagoshima Prefecture, Japan. Sixty-two Holstein cows in the farm were treated with 0.5 mg/kg of eprinomectin and then evaluated for pruritus behavior, lesions, cow comfort, and milk yield. Furthermore, cows were divided into two groups by the presence or absence of pruritus behavior, and lesions and milk yield were then compared. The rates of both tail swishing indicating pruritus and lesion score significantly decreased after treatment. The rate of standing idle, an indicator of cow comfort, significantly decreased and the 305-day corrected milk yield increased after treatment. While the tail swishing-positive group had a higher lesion score and little variance in milk yield after treatment, the tail swishing-negative group had an increase in milk yield. Thus it can be said that the eprinomectin treatment had therapeutic efficacy on bovine chorioptic mange. In addition, our data suggests that it could be important to treat in the early stage of dermatitis onset to maintain cow comfort and the productivity of affected cows.
