Spontaneous glomerulonephritis in swine.

In this investigation, 32 cases of naturally occurring glomerulonephritis in swine were studied retrospectively (1973-1993). Almost all affected pigs were crossbred and more than half were growing pigs. Nearly two thirds of the pigs showed gross renal lesions characterized by bilateral kidney enlargement, palor, edema, and/or cortical petechiation. The most commonly encountered extrarenal lesions were serous bodily effusions and gastric ulcers. The renal disease was considered the primary cause of death in 11 pigs. Histologically, the renal lesions in all pigs were characterized by a generalized and global proliferative glomerulonephritis. Mesangioproliferative glomerulonephritis was diagnosed in 2 pigs, whereas the glomerular lesions found in the other pigs (30/32) were characterized by a proliferative and exudative glomerulonephritis frequently associated with crescent formation. In all pigs, there was histologic evidence of proteinuria. A focal necrotizing vasculitis was found in the kidneys of 7 pigs. Although probably of immune origin, the precise etiopathogenesis of the porcine glomerulonephritis described herein after remains unknown.