Renal glomeruli of 9 dogs and 5 cats infected with Dirofilaria immitis and 19 hamsters infected with Dipetalonema viteae were studied ultrastructurally. Other major organs from infected hamsters were studied with the light microscope. One or more of the following pathological changes were found in the infected dogs: glomerular basement membrane (GBM) thickenings, GBM dense deposits, GBM holes, fusion of epithelial cell foot process, increased numbers of epithelial cell microvilli, increased numbers of mesangial cells, and occurrence of lysosome-like residual bodies in mesangial cells. Glomerular basement membrane thickenings, GBM dense deposits, GBM holes, GBM nodules and subendothelial dense deposits occurred in heavily infected hamsters. Amyloid fibrils and virus-like inclusions were also found in some infected hamster glomeruli. The pathological changes in hamster glomeruli appear to be associated with microfilaremia. Abnormalities were not found in cat glomeruli examined. Light microscopy revealed mononuclear and eosinophilic cellular infiltrations in the liver of all infected hamsters. These liver lesions were not found in any of 12 control animals examined. The observations made in this study suggest that glomerular lesions are another complication of filariasis.
Present address: Department of Biology, Millersville State College, Millersville, Pennsylvania 17551.