Cryptorchidism in North Ronaldsay sheep.

The incidence of cryptorchidism in ram lambs of the North Ronaldsay breed was recorded between 1998 and 2005. The overall incidence of cryptorchidism was 7.4 per cent (ranging from 2.4 per cent to 18.2 per cent in different years). In 87.3 per cent of the cases only one testis was retained, with the right testis being affected in 78.5 per cent of all the cryptorchids.