'It was painful to declare it': outbreak of animal disease was blow to Sudan exports

Rift Valley fever led to temporary block on trade, with devastating impact on farmers and livestock

• 'Live animals are the largest source of infection': dangers of the export trade

Thousands of sheep waiting to be exported ended up dying of hunger and thirst, after an outbreak of Rift Valley fever led to a temporary Saudi block on trade.

The appearance of the disease in any country that depends on the export trade is potentially catastrophic. Countries are supposed to notify the World Organisation for Animal Health (OIE), which will then place restrictions on their trade.