Differential diagnosis must be made rapidly because of its resemblance to foot and mouth disease. Spread to dairy herds will cause substantial economic losses. The OIE characterizes VS as a List disease that could rapidly spread across international borders, causing serious loss to agriculture. Therefore the presence of VS is cause for restricting the expor tof livestock from an affected country to VS-free areas. The economic costs from lost trade, closed sale barns, rodeos and livestock shows were ca.
Infection can result in vesiculation, epithelial cell lysis and severe interstitial edema.
Lesions progress by extension, such that it is common for the entire epithelium of the tongue or teat to be sloughed. It is likely that the presence and duration of viremia and the extent of virus load in VS infected livestock may vary with the severity of disease. Because relatively few VS infected animals show severe clinical signs of disease, the host immune response is likely important in determining the outcome of infection. VS has been shown to induce high levels of nitric oxide in vivo. Therefore shedding of VS or prolonged viremia may be the result of an inadequate or poor host response.