Scientists across Europe and the United States are following the emergence of a new Transmissible Spongiform Encephalopathy (TSE) in cattle that could be a new strain of BSE.

Speaking last weekend at an international conference on prion diseases in domestic livestock (such as BSE in cows and scrapie in sheep and goats) scientists from France and Italy described how the disease had been detected in a small number of cattle ranging from five to 15 years old.

The strain differs from BSE in that it has a longer incubation time and is consequently being found in older cattle.

The new strain also demonstrates different characteristics from BSE in laboratory tests and was originally detected through active surveillance of live animals rather than during inspection of a suspect fallen animal.

Marion Simmons of the Veterinary Laboratory Agency at Weybridge urged caution saying there are not yet sufficient supporting data to suggest that the disease is a new strain of BSE.