Proteinuria associated with glomerulosclerosis and glomerular collagen formation in three Newfoundland dog littermates.

Three dogs out of a litter of eight Newfoundland dogs developed a progressive fatal glomerulopathy. The affected dogs were a 2-month-old male, a 2.5-month-old female, and a 1-year-old male. The disease in all three animals was characterized by growth retardation, anorexia, proteinuria (14-16 g/liter), hypoalbuminemia (15-21 g/liter, elevated plasma urea (13-28 mmol/liter), and creatinine (83-296 mumol/liter) concentrations. Because of a bad prognosis the dogs were euthanatized. On postmortem examination, the animals had enlarged, slightly pale kidneys, which revealed glomerulosclerosis and glomerulofibrosis on histologic and electron microscopic examination. The lesions consisted of subendothelial and mesangial collagen fibrils and an increase of mesangial matrix. The fibrosis may result from endothelial or mesangial collagen formation as the manifestation of a metabolic disease.