The Welsh government said on Thursday that a dead cow on a farm in Wales had been confirmed as having bovine spongiform encephalopathy, known as mad cow disease, but said it had not entered the food chain and there was no risk to human health.
Rebecca Evans, the Welsh Assembly's Deputy Minister for Farming and Food, said there had been a number of sporadic cases of BSE across Britain in recent years with the last case in Wales in 2013.
She said officials were working to investigate the circumstances of the case. Since BSE was first identified in Britain in 1986, strict controls have tempered the spread of the disease.
"Identification of this case demonstrates that the controls we have in place are working well," she said in a statement.
She added that while the disease was not directly transmitted from animal to animal, the dead cow's cohorts, including offspring, had been traced, and would be destroyed in line with EU rules.