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EXPERIMENTAL strain typing of variant Creutzfeldt-Jakob disease (VCJD) has shown that the transmissible agent respon-sible for this disorder is identical to that in bovine spongiform encephalopathy (BSE), providing further evidence to support the hypothesis that exposure to the BSE agent, presumably through the diet, is the cause of VCJD (Ironside 1998). Most cattle are stunned with a captive bolt gun (CBG) before slaugh-ter and because of the suggested link between BSE and VCJD, the possibility that the use ofCBGS may contaminate the carcase with brain tissue has raised concern for public health.

Garland and others (1996) previously reported the finding, at necropsy, ofbrain tissue in the lungs of cattle slaughtered in the USA after being stunned with a pneumatically activated, penetrating CBG that introduced air intracranially. However, the validity and relevance of the Garland report was ques-tioned (Taylor 1996) and similar studies carried out on 210 cattle in UK abattoirs failed to confirm this observation (Munro 1997). The UK Meat and Livestock Commission issued a press release on September 29, 1996, stating that the report hadno relevanceto the meat industry in Britain (Anon 1996). However, relatively crude and insensitive procedureswere used in these studies for the detection of central nervous system (CNS) material. Concern, therefore, remains that the stunning and slaughter procedures that are prevalent in Europe and the USA may possibly, if used in an animal that had BSE, cause con-tamination of the edible parts of the carcase with brain tissue containing high titres of infectivity, and therefore expose the consumer to the …