Familial renal disease in Norwegian Elkhound dogs: morphologic examinations.

Periglomerular and interstitial fibrosis were the earliest renal lesions in 21 Norwegian Elkhound (NE) dogs with familial renal disease. Histopathologic study did not reveal the cause of the disease, and light microscopy did not show renal lesions different from nonfamilial renal lesions commonly observed in dogs. Histopathologic evaluation was reliable for detecting disease in NE dogs prior to onset of isosthenuria and azotemia. Results of glomerular counts, determining kidney size, and dissection of the nephron indicated that nephron numbers and size were adequate early in the disease, but that numbers decreased as the disease progressed. Electron microscopic and immunofluorescent studies were not suggestive of an immune basis of the renal disease, nor did histopathologic or angiographic studies indicate primary vascular lesions. Nephron dissections revealed sacculations in distal tubules and collecting ducts of affected NE dogs. Renal disease did not develop in mongrel pups given injections of an homogenate or renal tissue from an affected NE dogs.