Fecal Glucocorticoid Metabolites as a Noninvasive Indicator of Stress in the Tsushima Leopard Cats (Prionailurus bengalensis euptilurus): Application to Health Care

SIMPLE SUMMARY: The Tsushima leopard cat (Prionailurus bengalensis euptilurus) and the Iriomote cat (P. b. iriomotensis) are the only two wild felids living in Japan. Both species are endangered. The Tsushima leopard cat is undergoing captive breeding (ex situ conservation) in zoos with the aim of returning it to the wild, in addition to conservation activities in the habitat (in situ conservation). In order to promote captive breeding, it is important to elucidate the reproductive physiology and to evaluate stress conditions. We investigated the possibility of measuring glucocorticoid metabolites (GCMs), which are stress hormones, using feces in Tsushima leopard cats. We examined changes in fecal GCM in individuals who underwent a health examination under anesthesia as an unavoidable stressful condition during normal health care. Fecal GCM concentrations increased 1–2 days after the health examination. Fecal GCM concentrations were higher in diseased individuals than in apparently healthy individuals. Individuals diagnosed with disk herniation also showed a decrease in fecal GCM concentrations after treatment with therapeutics. These results indicate that the measurement of fecal GCMs is useful for improving the husbandry and health management of the Tsushima leopard cat. ABSTRACT: This study investigates whether the measurement of glucocorticoid metabolites (GCMs) in feces is a useful method for the noninvasive evaluation of stress in the endangered Tsushima leopard cats (Prionailurus bengalensis euptilurus). Feces were collected from six seemingly healthy and five diseased (renal dysfunction, adrenal tumor, hernia, feline immunodeficiency virus (FIV), feline leukemia virus (FeLV)) Tsushima leopard cats in captivity. Fecal GCMs were measured by enzyme immunoassay (EIA) for cortisol. Individuals that experienced a physical examination under anesthesia showed increased fecal GCMs 1–2 days after the event. An individual diagnosed with disk herniation showed decreased fecal GCMs after medical administration. The mean fecal GCM concentrations for six healthy animals and five diseased animals were 0.66 ± 0.08 and 2.65 ± 0.76 μg/g, respectively, which was significantly different. Cortisol and corticosterone were not clearly detected in the feces examined by the use of the HPLC-EIA analysis. GCMs may be excreted in the feces; however, the exact identification of these substances is not achieved. The results suggest that the measurement of fecal GCMs is useful for the husbandry and health management of this species.