The disease appears contagious, and incidence is much higher during wet, humid weather or when conditions are wet underfoot. Stony ground, lanes filled with sharp gravel, and pasture of coarse stubble also predispose to the condition. Discharges from the feet of infected animals are the probable source of infection.
Bacteria enter through abrasions into the skin on the lower part of the foot.
Such abrasions are more likely to occur when the skin is swollen and soft due to continual wetness, such as often occurs from rain in summer and autumn months. Persistent wet conditions also may favor persistence of the bacteria on pasture land. The disease is common in most countries and is of greatest economic importance in dairy cattle. It reaches the highest level of incidence in dairies, because of the intensive conditions under which the cows are kept. In beef cattle on range, the incidence is usually low, but many cases may occur in purebred herds and feedyard cattle.