Mucopolysaccharidosis VII in a cat

Mucopolysaccharidosis VII was diagnosed in a domestic shorthair cat from Ca lifornia. The cat was small and had multiple abnormalities, including a sma ll body disproportionate to the size of the skull, angular deformities of t he ribs, abnormally short forelimbs, luxating patellas, generalized epiphys eal dysplasia involving the vertebrae and long bones, cuboidal vertebrae, p ectus excavatum, subluxation of both hips, osteosclerosis of the tentorium cerebelli and left petrous temporal bone, tracheal hypoplasia, and corneal clouding. beta-Glucuronidase activity was markedly decreased in peripheral blood leukocytes. The cat died at 21 months of age, and a complete necropsy was performed. Tissues were examined by light and transmission electron mi croscopy. Large clear, round vacuoles representing distended lysosomes were present in many epithelial and connective tissue cells, including fibrocyt es, chondrocytes, smooth muscle cells, hepatocytes, astrocytes, and macroph ages.