The few cases of BSE (bovine spongiform encephalopathy), or "mad cow disease", in cattle in Canada and the US, and the single case of BSE recently confirmed in a goat in France should not cause panic among consumers and producers, the UN Food and Agriculture Organisation (FAO) has said.

"The three cases in Canada and the one case in the US from an imported animal are isolated incidents," said Andrew Speedy, an FAO animal production expert. The FAO said such cases were detected because of the testing procedures that are now in place.

The FAO said the goat diagnosed with BSE in France was the first food animal other than cattle to contract the disease naturally. It was thought that sheep and goats were only affected by scrapie which is distinguishable from BSE and not thought to be transmissible to humans. But FAO stressed that this is one example in millions, and the goat was born before Europe imposed a total ban on feeding of meat and bone meal to livestock in January 2001.

BSE is a fatal disease of adult cattle characterised by degeneration of the central nervous system. The causative agent is thought to an abnormal form of a protein called a 'prion'. BSE was first diagnosed in cattle in the United Kingdom in 1986. The transmission of BSE is thought to be by the oral ingestion of animal feed containing BSE-infected meat and bone meal.

Scientists believe that BSE causes variant Creutzfeldt-Jakob Disease (vCJD) in humans, by consumption of contaminated beef products from infected cattle. The disease has caused 148 deaths in the last ten years, almost all in the UK.