• Journal of Veterinary Clinics
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• v.26 no.5
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• pp.450-456
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• 2009

This study evaluated the efficacy of topical eprinomectin (0.5% pour-on solution, $Eprinex^{(R)}$, 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 ($Eprinex^{(R)}$, 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.

• Parasites, Hosts and Diseases
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• v.46 no.4
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• pp.273-278
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• 2008

Mites in the genus Chorioptes cause a mild form of skin disease in both domestic and wild ruminants. In July 2006, dermatitis characterized by alopecia, marked lichenification, accumulation of crust, and fissuring was recognized in 14 out of 200 Holstein dairy cattle raised in the cattle farm of the National Institute of Animal Science in Cheonan, Republic of Korea. Skin lesions were distributed mainly over the tail base, and sacral and perineal regions. Microscopic examinations of skin scraping samples from severely affected areas revealed numerous mites of all developmental stages. Morphologically, pedicels of the mites were short and unjointed. The tarsal suckers occurred on the pedicels of all the legs in the male worm and on the first, second, and fourth pair of legs in the adult female worm. A single long seta at the tarsus of legs III and the length of legs II being about twice as long as legs IV in adult male mites were observed. Arising anterior to the inner-most spatulate seta was a short seta with an average of $26.4{\pm}5.8{\mu}m$ in length. Also, the length of setae #4 on the opisthosomal lobes was relatively short. Based on these observations, the mites were identified as Choriptes texanus. Although the chorioptic mange may not influence the mortality rate in the affected farm, reports indicate that a decline in milk production can be observed. This is the first report of chorioptic infestation in a cattle farm from Korea.