What animals are affected by BSE?

To date, mainly cattle have been detected with BSE (some examples in cats and felines have been reported). There is a theoretical risk of BSE in sheep but to date no sheep has been demonstrated to have contracted BSE, except experimentally in very extreme conditions in laboratories.

Some scientists believe that scrapie, a TSE disease affecting up to 10,000 sheep in the UK every year, could be concealing BSE or a BSE-like disease in sheep. Scrapie has been present in sheep flocks for more than 200 years and spreads naturally between sheep although the exact mode of transmission is not well known: infected placenta seems to be the major transmission factor both for newborn and adult, licking or eating the infected stuff. Scrapie has not been shown to affect humans.

TSEs, including BSE and scrapie, have not been found to occur naturally in chickens, pigs, rabbits, horses and dogs.

Preliminary results of studies in lemurs in zoos in France which were fed beef protein supplements suggest that BSE infection in primates occurs when the animals are fed with BSE-infected feeds. The studies support BSE-infected meat-and-bone meal as the source of BSE infection.