There are 7 main types of the Foot and Mouth virus
There are 7 main types: O, A, C, SAT.1, SAT.2, SAT.3 and Asia 1. Within each type there are many sub-types, for example, O1 and A22. The average incubation period is 3 to 8 days but it can be shorter or may extend to 14 days or longer. The virus responsible for the 2001 outbreak in the UK was the highly virulent pan-Asiatic O type. When animals recover from infection by 1 type of virus they have little or no protection against attacks by any one of the others.