NATURALLY-OCCURRING CEREBRAL NEMATODIASIS DUE TO BAYLISASCARIS LARVALMIGRATION IN 2 BLACK-AND-WHITE RUFFED LEMURS (VARECIA-VARIEGATA-VARIEGATA) AND SUSPECTED CASES IN 3 EMUS (DROMAIUS-NOVAEHOLLANDIAE)

During September and October 1992, two black-and-white ruffed lemurs ( Varecia variegata variegata) were housed in an outdoor wire enclosure at the Tulsa Zoological Park. The following February and April, both l emurs developed head tilt and ataxia, and they were euthanized. Necrop sy revealed multifocal malacia of the white matter of the pens, cerebe llum, internal capsule, and cerebral and cerebellar peduncles. Nematod e larvae consistent with Baylis-ascaris spp, were observed in the brai n of one lemur. A retrospective study revealed three cases of ataxia i n emus (Dromaius novaeholloandiae) that were previously housed in the same enclosure. Archival paraffin-embedded tissue from one emu reveale d tractlike foci of malacia within the white matter of the cerebellum. Circumstantial evidence, including the observation of numerous raccoo ns (Procyon lotor) in the vicinity, and the presence of numerous Bayli s-ascaris procyonis in the intestine of a single trapped raccoon impli cate this roundworm as the pathologic agent in the lemurs.