Breast burns in chickens and breast buttons in turkeys are localized lesions affecting the skin in a location similar to that of breast blisters Breast Blisters in Poultry Fluid-filled sternal bursa characteristic of breast blister on the keel of a turkey. Chickens and turkeys have a synovial membrane in the subcutis on the ventral and anterior aspects of the... read more . They have a hard crust on the surface and a core of dead skin and chronic inflammation extending into the subcutis. The cause is not well defined, but a breast burn or button may start as a chemical burn due to prolonged contact of skin with wet litter containing ammonia or toxins. The conditions are more frequent with increased stocking density, increased age, particular feeds, male birds, and winter. The presence of good quality, dry litter is associated with a reduced number of affected turkeys.