sore mouth

noun

1

: a highly contagious virus disease of sheep and goats that is caused by a poxvirus (species Orf virus of the genus Parapoxvirus), occurs especially in young animals, is characterized by extensive vesiculation and subsequent ulceration about the lips, gums, and tongue, and rarely ends fatally but interferes with nutrition and may be complicated by secondary bacterial infection

called also orf, scabby mouth

2

: necrobacillosis affecting the mouth

especially : calf diphtheria