Enzootic calcinosis in sheep and C-cells hyperplasia of the thyroid

In nine sheep belonging to the same flock, C-cells hyperplasia of the thyroid, associated with calcinosis of the soft tissues is reported. The C-cells hyperplasia was probably due to excessive feeding with poultry waste, rich in calcium. The soft tissue mineralisation was a result of hypersecretion of calcitonin, a blood calcium-lowering hormone of the C-cells.