Enzootic calcinosis (EC), by ingestion of toxic plant Solanum glaucophyllum, is a well-known chronic disease in Argentina affecting cattle under extensive grazing systems. It is characterized by systemic calcification of soft tissues, that can progress to death when severe cardiovascular lesions are present. We describe an episode of EC in sheep after exposure to hay contaminated with S. glaucophyllum. In a sheep flock of 17 male, 8-10 months old, 2 died spontaneously. Grossly, hydrotorax, lung edema, and aorta artery and myocardial multifocal-coalescing mineralization was observed. Microscopically, systemic mineralization of blood vessels was present in aorta, kidney and heart characterized by basophilic granular deposits in tunica intima and/or tunica media. Myocardial multifocal-coalescing areas of myofiber loss and regeneration, characterized by macrophage and satellite cell infiltration intermingled with fine granular basophilic deposits (mineralization) was evident. Von Kossa stain confirmed mineralization as calcium deposits. Furthermore, sheep outbreaks are sparsely reported, contributing to knowledge of the disease in other species, in addition to cattle, and in an unusual presentation as forage reserves. During hay production, inspection of possible toxic plants, such as S. glaucophyllum, must be carried out.