A Collective Outbreak of Bovine Demodicosis

Abstract

On a dairy farm in the Tokachi district of Hokkaido bovine demodicosis was seen in 5.3%(2/38) of calves and 44. 6%(25/56) of cows 2-14 years old in July, 1982. Large numbers of nodules caused by Demodex bovis were observed on the body side, head, back, hip, legs and abdomen. Every stage of D. bovis was detected in materials squeezed from nodules, and most male adults were seen in the crust of nodules. A 5 v/v% dilution of 20% BPMC (2-sec-butylphenyl-methyl-carbamate) in liquid paraffin was applied to 2 heavily affected animals once a week for 5 weeks. As a result, nodules were reduced in number to 78.4 and 62.3% respectively, at 13 weeks of treatment.