The incubation period ranges from two to 14 days but many animals show signs within a week of infection. Following inhalation, the virus spreads throughout the body and infects many tissues. The disease in cattle is characterised by fever, depression, loss of appetite and a drop in milk production and, later, by vesicles in particular locations. Affected cattle drool saliva, often accompanied by smacking of the lips. Lameness is evident and pregnant cows may abort.
Vesicles rupture quickly leaving raw ulcers which heal gradually over two to three weeks.
Bacterial infections may delay healing. In pigs, marked lameness is the main presenting sign. Foot lesions are severe in pigs and hooves may slough. In sheep, goats and wild ruminants, the disease is usually milder and careful examination may be required to detect lesions. Rapidly spreading lameness accompanied by fever may be evident in groups of sheep.