Assessment of the impact of handling time on blood parameters in healthy Grand Cayman blue iguanas (Cyclura lewisi)

Intensive captive breeding, head starting, reintroduction, individual and population health monitoring, and habitat protection for the past 20 years are credited for the ongoing recovery of the endangered Grand Cayman blue iguana (Cyclura lewisi). Comprehensive health assessments ensure only healthy animals are released, minimize the risk of inadvertent introduction of pathogens into free-ranging populations, and establish baseline health parameters for future reference and disease surveillance. These examinations require capture and manual restraint, which may result in a physiological, glucocorticoid-mediated stress response, resulting in significant alterations in blood parameters that positively correlate with duration of restraint. This study analyzed plasma biochemistry and hematology data from 820 examinations of healthy captive and free-ranging blue iguanas of both sexes and age ranges from approximately 1 to 33 years old; representing 601 individuals, sampled over 9 years (2009-2017), and the relationship of these values to handling duration prior to venipuncture. In captive blue iguanas there was a significant correlation (P < 0.05) of handling time with changes in blood parameters for aspartate aminotransferase, bile acids, blood urea nitrogen, glucose, lipase, phosphorus, and uric acid. Alterations in aspartate transaminase, bile acids, blood urea nitrogen, glucose, phosphorus, total bilirubin, and uric acid were significant (P < 0.05) when stratified by sex and handling time. Clinical significance of these changes appears to be minimal compared to species reference ranges.