Prevalence of contagious pustular dermatitis (orf) in six million lambs at slaughter: a three-year study.

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 pustular dermatitis (CPD). The proportion of lambs affected was highest in the months of December and January when up to 2.2% of the lambs 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. If it was decided to reject for slaughter lines with CPD, approximately 1 1/4 million lambs would be returned to farms each year. It was concluded that such a policy would be unlikely to substantially reduce the level of infection in meat workers.