This study evaluated the efficacy of topical eprinomectin (0.5% pour-on solution, Eprinex? Merial) against
Chorioptes texanus (C texanus) infestation in dairy cows reared in Korea. Dairy cows naturally infected with C texanus
showed skin lesions as alopecia, erythema, excoriations and crusts on the tail head, the caudal folds, the back of udder
and the rump area. Fourteen adult Holstein dairy cows with chorioptic mange at National Institute of Animal Science
were selected on the basis of gross lesion and microscopic examination. Experimental dairy cows infected with
chorioptic mange were treated with eprinomectin (Eprinex? Merial, France) at the rate of 1 ml /10 kg/BW. Evaluation
of therapeutic effect is based on mite counts and gross lesion at weekly interval for 6 weeks. Milk yields were measured
every day and calculate at the mean of milk yield at weekly interval. Mange mites absolutely removed after 1 week
of topical eprinomectin against C. texanus infestation on dairy cows. The skin lesion of dairy cows infested with C.
texanus recovered normal status after 6 weeks of eprinomectin treatment. After eprinomectin treatment, return to the
normal level of milk yields in diary cows infested with C. texanus has indirectly indicated that C. texanus infestation
have negative effect on productivity of dairy farm. However, it would be suggested that the investigation of actual
condition and the effective control method of C. texanus infestation of dairy farms in Korea should be studied in
the future.