The Office International des Épizooties (OIE), the world animal health organisation, will review its guidelines on trade with countries with BSE outbreaks following requests from the USA, Canada and Mexico, but claims governments are already failing to implement its existing advice.

The north American trio requested action because of the complete bans on buying Canadian beef following the discovery of one BSE infected cow this year.

But the OIE says that its current rules oppose such stringent action anyway. It said its code "has never suggested a total embargo of animals and animal products coming from BSE infected countries, even from countries considered as having "high BSE risk".

It added: "In some cases, embargos are carried out without a science based risk analysis."