Assessment of Corticosterone Levels in American Alligators (Alligator mississippiensis) with Dermatitis

Bacterial and fungal dermatitis is a common problem in captive reared alligators in commercial operations, and stress has been suggested as a predisposing factor. We compared corticosterone levels between alligators with dermatitis (Tx) and alligators without dermatitis (Cx). There was no statistically significant difference between the baseline corticosterone concentrations (time 0) of the Tx and Cx groups ( P = 0.272). At 15 min postcapture, there was a statistically significant difference between treatment and control animals ( P = 0.006), with the Tx alligators having higher corticosterone concentrations compared with the Cx alligators. At 3 h (after dexamethasone administration) values for both groups decreased from the 15 min levels, showing a functional negative feedback loop of the hypothalamic–pituitary axis; there was no statistically significant difference between groups ( P = 0.90) at that time. The results do not show an association between stress and dermatitis, but suggest that animals may be more prone to increases in corticosterone release once dermatitis is present.