An outbreak of lymphosarcoma in merino sheep in the South Western Cape.

Ten per cent of a flock of 481 Merino sheep died from suspected lymphosarcoma in the Caledon district, during a period of one year. In 9 sheep the diagnosis was confirmed by histopathological examination of the tumours. All the sheep and the cattle on the farm were tested for enzootic bovine leukosis using a Bovine Leukemia Glycoprotein Immunodiffusion kit. At the first test 20.5% of the sheep had antibodies to enzootic bovine leukosis. A control programme resulted in a drop in infection rate (3%) within 17 months.