A case of juvenile nephropathy in a two-year-old Weimaraner bitch is reported. Although Juvenile nephropathy has been described in several breeds of dogs, this is the first report in a Weimaraner. Clinical aspects, blood analysis, renal pathology and extrarenal changes are described. The renal changes consisted of tubular as well as glomerular lesions, similar to those described in the miniature schnauzer. The main extrarenal lesion was degeneration and necrosis of subendocardial myocytes in the left atrial wall associated with an inflammatory reaction and focal necrotising arteritis.