At the San Diego Zoo, renal lesions occurred spontaneously in 22 of 113 prosimian primates, 17 of them in the family Lorisidae (14 in galagos), three in Lemuridae, and one each in Indriidae and Tupaiidae. Of the Galago cases, six were in G. senegalensis and eight in G. crassicaudatus panganiensis. Lesions included focal and diffuse proliferative glomerulonephritis, membranoproliferative glomerulonephritis, interstitial nephritis, and pyelonephritis.