Sites of infection are most commonly the lips or nose, but the udder, teats and junction of the hoof and lower legs may also be infected. These areas become blisters or pustules for a short period of time and may run together to produce larger areas of infection. Over a one week period of time, scabs form over infected areas. These scabs fall off after about 3 weeks, revealing rough reddened areas of granulation tissue. Once all scabs have fallen off, the infection is considered inactive.
Affected lambs are depressed and reluctant to nurse or eat.
Ewes with udder or teat lesions may not allow nursing and their lambs may spread the disease by attempting to nurse young lambs. Ewes with udder or teat lesions are also much more susceptible to Staphylococcal mastitis which often results in loss of the udder half or death of the ewe. The diagnosis of soremouth is generally based on clinical signs alone and laboratory testing of animals is usually not of much use or not available. The Soremouth virus is spread to people by contact with infected sheep. The infection in usually is seen on the hands or face.