Pustular dermatitis is usually observed only in nursing piglets. It is caused by a beta-hemolytic, Lancefield type C, streptococcal infection. Pustules appear in the inguinal area and inner surface of the rear legs but occasionally occur at other locations. The pustules soon rupture and are replaced by dark brown to black crusts. The streptococci are easily isolated from pustules. The piglets usually recover spontaneously. Recovery may be hastened by treatment with an appropriate antibiotic.