Abstract :
Enzootic calcinosis associated with Nierembergia veitchii ingestion occurs in sheep in
southern Brazil, and has been described as a chronic disease. However, in recent years
this plant has been associated with cases of acute disease and sudden death in sheep.
Data from 12 sheep flocks affected by this toxicosis in southern Brazil, between 1990
and 2007, are described. Thirty-five sheep were necropsied. Twenty-four had a history
of chronic disease with weight loss, stiff gait, tucked abdomen, kyphosis, and recumbency.
Eleven sheep died suddenly with no prior history of severe illness. In all affected
sheep, gross changes included poor body condition and widespread mineralization of
several tissues, more prominent in blood vessels and heart valves. In addition, sheep
that experienced sudden death had moderate to severe pulmonary edema. There was
a distinct seasonal pattern to the clinical presentations, with chronic disease occurring
in spring and summer and the acute cases dying in fall and winter. Stress of parturition
or poor climatic/nutritional conditions may have precipitated the acute deaths.
