Cerebrospinal nematodiasis in a white-handed gibbon (Hylobates lar) due to Baylisascaris sp

An adult white-handed gibbon (Hylobates lar) at a zoo in eastern Kansas was euthanized after developing a head tremor, generalized motor incoordination, and partial paresis of the right arm that persisted over 2 yr. Magnetic resonance imaging early in the course of the disease demonstrated a localized left frontal lobe cerebritis. Larvae morphologically consistent with a Baylisascaris species were seen in tissue sections of the cerebrum and cerebellum. Epizootiologic investigation, which included qualitative fecal flotations, evaluation of soil samples for nematode eggs, and necropsy examination of livetrapped raccoons (Procyon lotor), indicated that Baylisascaris procyonis was most likely to have caused the cerebrospinal nematodiasis in this gibbon.