The role of management segregations in controlling intra-herd foot-and-mouth disease

Transmission of foot-and-mouth disease virus (FMDV) by aerosol spread can o ccur over considerable distances. However, this is less effective in hot, d ry environmental conditions, and a detailed study of an outbreak within a l arge dairy herd in Saudi Arabia has shown that contact spread is the main m ode of transmission within a herd: both physical and spatial barriers curta iled the course of disease across the farm. Hence, the speed and path of an outbreak can be altered by changing the positioning of spatial or physical barriers. Extending the distances between pens, increasing the number of f arm pens, decreasing the number of animals within the pens, and placing pen s of well-protected stock between those of susceptible stock, can all contr ibute to the control of FMD involving contact and short-distance aerosol sp read. Such management techniques offer a cost-effective supplement to contr ol by vaccination.