2003 Volume 56 Issue 12 Pages 798-800
As a result of genotypic examination, a 1.5-month-old Japanese Black calf was diagnosed as homozygotic for Claudin-16 (CL-16) deficiency. The animal suffered from watery diarrhea, dehydration, dysstasia, and clonic spasms. Hematological analysis revealed renal damage, hypocalcemia, and hypomagnesemia. Urinary sediment included many renal tubular epithelial cells. Necropsy showed both kidneys to be small. Histological examination showed degeneration, necrosis, and desquamation of renal tubular epithelial cells, marked thickened renal-tubule basement membranes, and marked interstitial fibrosis. These conditions may account for the abnormal formation of tight junctions between renal tubular epithelial cells caused by CL-16 deficiency.