Administration of moxidectin for treatment of sarcoptic mange in a flock of sheep

The treatment of a large flock (1529 sheep) infested with Sarcoptes scabiei is reported. All sheep of the flock were treated twice, 12 days apart, with moxidectin 1% injectable solution, given subcutaneously at 0.2 mg kg(-1) bodyweight. Skin lesions were scored on a 0 to 4 scale and skin scrapings were obtained to detect presence of mites, prevalence of skin lesions was 10.5% before the first injection; 19, 26, 40, 68, and 96 days later, it was reduced to 6.3%, 5.3%, 3.2%, 0.7% and 0%, respectively. Mean lesion score was 0.183 before the first injection; 12, 19, 26, 40, 68 and 96 days later, it was reduced to 0.144, 0.082, 0.064, 0.038, 0.007 and 0.000, respectively. Mites were isolated from 80% of sheep sampled before treatment, from 40% of sheep sampled 12 days after the first injection and from 10% of sheep sampled 19 days after it; no mites were isolated thereafter. It is concluded that the above treatment regime completely cured sarcoptic manage. Furthermore. it is underlined that a health improvement observed after the first injection should nor encourage the omission of the second one and that lack of complete healing of the skin lesions should not be interpreted as persistent infection. (C) 1999 Elsevier Science B.V. All rights reserved.