Glomerulocystic Kidney in a Domestic Dog

Glomerulocystic kidney was diagnosed in a 5-year-old female Shiba dog, which died from chronic renal failure with convulsions, vomiting and diarrhoea. Haematological examination revealed non-regenerating anaemia, azotaemia and high serum creatinine. Grossly, both kidneys were mildly atrophic with multiple small cysts in the cortex. Histopathological examination revealed marked dilatation of Bowman's space, often with glomerular atrophy or loss, and mild interstitial fibrosis. Bowman's basement membranes (BMs) were tortuous and thickened, with patchy calcification. Glomerulo-tubular junctions in the urinary pole side of the kidneys had a stenotic appearance associated with thickening of Bowman's BMs and calcification. Focal interstitial fibrosis around the glomerulo-tubular junction was also found. Continuity with the proximal tubule was evident in cystic glomeruli. Ultrastructurally, marked thickening of Bowman's BMs with many granular deposits in the urinary pole side was observed. The findings indicate that glomerular cystic changes may have developed as a consequence of glomerulo-tubular junctional stenosis due to thickened Bowman's BMs and focal periglomerular fibrosis in the urinary pole side of the kidneys.