ETHYLENE-GLYCOL TOXICOSIS IN A CAPTIVE-BRED RELEASED CALIFORNIA CONDOR (GYMNOGYPS CALIFORNIANUS)

A male and a female California condor (Gymnogyps californianus), one h atched at the Zoological Society of San Diego and the other at the Los Angeles Zoo, were released at approximately 9 mo of age in the Sespe Condor Sanctuary. Nine months after release, the male bird was found d ead. Gross examination was unremarkable. Histopathologically, numerous tubules throughout the kidney contained clear to slightly yellow-brow n, granular to irregular acicular, occasionally radiating, slightly re fractile crystals. The crystals were highly birefringent in polarized light and caused mild to moderate disruption and necrosis of affected tubular epithelium. The crystals did not dissolve in formalin and were negative with urate staining. Renal calcium levels were markedly elev ated (2,307 ppm; normally <500 ppm for most avian species), ethylene g lycol was present at 502 ppm, and trace amounts of propylene glycol we re also detected. Analyses of various tissues for heavy metals, trace elements, alkaloids, insecticides, and polychlorinated biphenyls revea led no remarkable abnormalities. Based on all findings, the kidney cry stals were interpreted to be calcium oxalate, and a diagnosis of acute ethylene glycol toxicosis was made. The source of exposure was not de termined.