Animals carrying the virus are introduced into susceptible herds. Contaminated facilities are used to hold susceptible animals. Contaminated vehicles are used to move susceptible animals. Raw or improperly cooked garbage containing infected meat or animal products is fed to susceptible animals. Susceptible animals are exposed to materials such as hay, feedstuffs, hides, or biologics contaminated with the virus.
Susceptible animals drink common source contaminated water.
A susceptible cow is inseminated by semen from an infected bull. Airborne spread of the virus can take place and under favourable climatic conditions the disease may be spread considerable distances by this route. The disease is characterized by fever and blister-like lesions followed by erosions on the tongue and lips, in the mouth, on the teats, and between the hooves. The resulting excessive salivating or lameness are the best known signs of the disease. Many affected animals recover, but the disease leaves them debilitated.