The pathology of an inherited lysosomal storage disorder of calves.

The clinical symptoms, gross and histopathological, as well as the ultrastructural appearance of a condition in cross-bred Aberdeen Angus calves resembling the inherited lysosomal storage disease, alpha-mannosidosis, are reported. The neurones and perithelial cells in the brain and the reticuloendothelial cells in the lymph nodes and spleen were extensively vacuolated. The vacuoles were filled with a sparse, flocculated to granular material within which membranous structures were frequently seen. No specific substance could be identified within the vacuoles, either histochemically or ultrastructurally. Besides the vacuolation, cystic tubular structures were seen in the kidneys. The lining epithelial cells of the thyroid follicles were vacuolated while some of the follicles contained no colloid.