EVALUATING ADRENAL ACTIVITY IN AFRICAN WILD DOGS (LYCAON-PICTUS) BY FECAL CORTICOSTEROID ANALYSIS

A noninvasive corticosteroid hormone monitoring technique was validate d for use in African wild dogs (Lycaon pictus). The double-antibody I- 125 radioimmunoassay for corticosterone was validated by demonstrating parallelism between serial dilutions of wild dog fecal extracts and t he standard curve, recovery of corticosterone added to fecal extracts, and the time course of fecal corticoid excretion after an exogenous a drenocorticotropic hormone (ACTH) challenge. All feces were collected from three female and two male African wild dogs for 72 hr before and 144 hr after i.m. injection of long-acting ACTH (Acthar Gel, 400 IU). Fecal corticosterone immunoreactivity increased 10-30-fold within 24 h r of ACTH administration in all individuals, with peak concentrations from 1,200-8,000 ng/g. High pressure liquid chromatography analysis re vealed that >90% of all corticosterone immunoreactivity was associated with a single peak that exhibited intermediate polarity relative to c ortisol and corticosterone reference tracers. Fecal corticosterone imm unoreactivity appears to reflect adrenal activity in the African wild dog and, therefore, may be useful for evaluating stress. From a conser vation perspective, these techniques can complement in situ and ex sit u research studies designed to evaluate how environmental conditions a nd management strategies affect overall animal health.