Control programmes create difficulties in trade between different regions or countries, as trade has the potential to introduce infectious diseases into regions where the disease is not present, which may lead to substantial economic losses.
Another problem is the lack of agreed methodologies to assess and compare health statuses, namely disease freedom or freedom from infection among cattle that are moved between different regions. Moreover, EU level control programmes are based on inputs, which mean that they prescribe for example: the study design, sampling scheme and diagnostic methods. In contrast, output-based control measures prescribe what needs to be achieved, but not in which way. Thus, output-based control can enhance the safety of animal trade, while allowing countries to prescribe control measures that they consider are the most suited for their circumstances.