Hypercalcemia in reptiles is generally associated with egg production in females, but may also be associated with excess supplementation, primary hyperparathyroidism, and osteolytic conditions. We noted extreme (>50 mg/dl) hypercalcemia in a singly-housed, approximately nine yo female prehensile-tailed skink (Corucia zebrata) and further investigated its significance. No evidence or notation of this condition was found in ISIS (International Species Information System) values or any other reference. In one species, the indigo snake (Drymarchon corais), it has been determined that hypercalcemia is a normal finding of healthy animals.1 By using data submitted by five institutions and analyzing the data using a mixed model analysis (variants are sex, health, season, and total protein), this study demonstrates that hypercalcemia in prehensile-tailed skinks is highly correlated with elevated total protein levels (p<0.0001). The main effects of sex and season were not significant factors in the model, but health and total protein were. However, the interactions between health and sex, sex and season, and health and season were significant. The etiology of the hypercalcemia is unknown, but is suspected to have a hormonal influence. Corucia zebrata is a viviparous species that is found in a tropical environment, where seasonal temperature variation is minimal (23–31°C), and it is undetermined if temperature, light cycle, or other factor is the seasonal "trigger." Additionally, it is unknown if the seasonal hypercalcemia demonstrated by this study occurs in free-ranging skinks, and will be an element of consideration for further study.
The authors thank the AZA institutions that supplied data for this study, including the Lincoln Park Zoo, the Columbus Zoo and Aquarium, the Philadelphia Zoo, the Wildlife Conservation Society, and the Cleveland Zoo.
1. Drew, M.L. 1994. Hypercalcemia and hyperphosphatemia in indigo snakes (Drymarchon corais) and serum biochemical values. J Zoo Wildl Med. 25(1):48–52.