Therefore, like influenza, resistance to one type does not completely protect against other types. The disease is not considered to be a threat to humans although humans can harbor the disease and occasionally develop mild symptoms. In susceptible animals, FMD causes blister-like lesions in the mouth, tongue, teats, and between the hooves. These blisters turn into erosions and ulcers. Early signs of disease may include fever and listlessness followed by drooling due to the mouth lesions.
Some animals become lame from lesions in the hooves.
Many affected animals recover. However, severe production losses may be incurred due to reductions in weight gain and milk production. In addition, the highly contagious nature of the disease means that almost all exposed animals are likely to become infected. The concern about FMD results from its potential to spread rapidly and widely, the likelihood for production losses, and the economic effects from market restrictions and embargoes if the disease appears. FMD is highly contagious.