Proliferative changes are active lesions, and potentially can be reversed. Proliferation of parietal epithelial cells is called cresents and in humans is usually irreversible. Similar information about cresent formation in dogs and cats is not known. Membranous GN is a thickening of the basement membrane. Membranoproliferative is a combination of proliferative and membranous.
Sclerosis is an end stage appearance and is irreversible.
The other morphologic types may progress to sclerosis. The lesions may be distributed diffusely through both kidneys or may be focal. Within an individual glomerulus the lesions may be segmental, global, or located in the mesangium. Animals which develop GN as a consequence of an infectious process are usually younger than those that develop GN as a consequence of neoplasia. There is no sex predisposition.