Bovine spongiform encephalitis (BSE) – more commonly known as ‘mad cow disease’ – has been found in a dairy cow in the US state of California, according to news agency Reuters. However the animal has contracted it in an atypical manner, meaning it had the disease spontaneously, and not through contaminated feed as in past cases in the UK, where the majority of BSE cases have been. This is the first case in the US since 2006, which has had three. Beef exports from the US dropped by 75 per cent in 2004 after the first incident in 2003.

The animal carcass is under quarantine and the US Department of Agriculture has started notifying the World Organization for Animal Health, as well as its trading partners. US Agriculture Secretary Tom Vilisack says in a statement: “The systems and safeguards in place to protect animal and human health worked as planned to identify this case quickly and will ensure that it presents no risk to the food supply or to human health.”