In the three years from October 1979 to September 1982 over 6.3 million lambs were processed in two meat works and of these 0.5% had lesions of contagious pustuiar dermatitis (CPD). The proportion of iambs affected was highest in the months of December and January when up to 2.2% of the Iambs slaughtered had lesions of CPD. On average 13.4% of a consignment (referred to as a line) of lambs showing evidence of CPD were affected. The total lambs in affected lines constituted 4.1% of the total slaughtered.