The histopathology of zinc deficiency in ducks.

Ducks maintained from hatching on zinc-deficient diets were retarded in growth and had severe lesions of the pedal epidermis, epithelia of the base of the tongue, oral surface of the larynx and nasal sinuses. Similar but milder changes affected the roof of the mouth, the crop and the oesophagus of a few cases. There was derangement of the architecture of the rete mucosum with loss of distinction between the cells of the stratum basale and stratum spinosum. Enlargement of the nuclei and nucleoli of these cells, widening of the intercellular space and dyskeratosis and degeneration, particularly of the prickle cells, were seen. Although epithelial atrophy occurred in early examples of the condition, acanthosis, hyperkeratosis and heterophil infiltration of the epithelial layers were characteristic of most cases. Erosion of the epithelium with the formation of purulent crusts ocntaining secondary bacterial foci was present and in these cases inflammatory phenomena occurred in the dermis. A small proportion of the nuclei of the pancreatic exocrine cells were enlarged and irregular in shape.