Chronic renal failure in young dogs–possible renal dysplasia

The clinico-pathological findings are described in thirteen young dogs with advanced renal disease. All but three dogs were less than 2 years old. Some had signs of renal dysfunction since birth. Presenting signs were variable but anorexia, lethargy and weight loss were most frequent. All dogs had raised blood urea levels and most passed dilute urine; proteinuria and anaemia were variable findings. At necropsy all dogs had extra-renal lesions of renal failure and finely granular or lobulated, shrunken kidneys. The microscopical appearances of the kidneys were not those of amyloidosis, inflammatory or glomerular disease but were considered likely to be of developmental origin. The renal lesions were divided into three histologically distinct groups.

• 1 Predominantly cystic and connective tissue changes, characterized by striking dilatation of glomerular capsular spaces and cortical tubules.
• 2 Atypical connective tissue changes in which there were segmental bands of fibrous tissue containing primitive glomerular and tubular structures.
• 3 Predominantly glomerular and connective tissue changes, characterized by varying degrees of glomerulosclerosis and widespread calcification of glomeruli, tubules and blood vessels.

All groups had cortical and medullary interstitial fibrosis but minimal inflammatory cell infiltrates.