In sheep and goats the disease is less serious, which actually makes it more of a problem. Because it can go unnoticed for longer than in cattle it is much more easily spread by movement of animals around the country and less easy to spot the symptoms. During the early stages of the epidemic in the UK, aheep are believed to have been the major vector whereby the virus was dispersed around the country. For this reason, the Ministry has ordered the mass slaughter of sheep and pigs known to have passed through markets known to have been infected, as well as flocks adjacent to farms where infection has been identified.
Pigs present a special problem.
In a week a single infected pig might exhale enough virus particles to theoretically infect every cow in Europe. So far the major intensive pig farming areas of Yorkshire, Lincolnshire and Norfolk have remained free of the disease. In anticipation of the scale of the threat to these areas, the army has established a command and control centre in Leeds. The spread of the disease to sheep on the upland fells presents a particular concern. The sheep on the fells are not fenced in, and so flocks belonging to different farms are free to mix freely.