Severe renal failure in a dog resembling human focal segmental glomerulosclerosis

A case of renal disease in a dog resembling human focal segmental glomerulosclerosis is presented. A kidney biopsy from this animal showed focal glomerular sclerosis, with variable distribution, affecting the perihilar and peripheral segments of the glomerular tuft. Non-sclerotic glomeruli were markedly enlarged. Interstitial fibrosis in association with tubular atrophy affected approximately 20% of the area of the biopsy. Immunofluorescence labelling showed immunoglobulin M deposits entrapped in segmental sclerotic areas and ultrastructural examination revealed segmental sclerosis and obliteration of capillaries, vacuolation of podocytes and diffuse effacement of foot processes. The dog was humanely destroyed 1 month later. At necropsy examination there was severe end-stage kidney disease with interstitial fibrosis involving more than 60% of the renal tissue. The clinical course and the microscopical, immunofluorescence and ultrastructural findings in this case have similarity to focal segmental glomerulosclerosis in man.