Evaluation of health parameters in cownose rays (Rhinoptera bonasus) housed in a seasonal touch pool habitat compared with an off-exhibit habitat

Cownose rays (Rhinoptera bonasus) are commonly displayed in zoo and aquarium touch pool exhibits; however, there is a gap in our understanding of how these practices might impact the health of these animals. The aim of this study was to evaluate and compare selected health parameters in cownose rays housed in a seasonal outdoor exhibit touch pool system with abundant public contact and an indoor off-exhibit holding system with minimal human contact. All animals underwent physical examination, ultrasound, cloacal wash and cytology, and blood collection for complete blood counts, point-of-care blood analysis, plasma protein electrophoresis, and plasma cholesterol electrophoresis in May and October 2014. Physical examination, ultrasound, and cloacal wash cytology findings were all unremarkable for both groups of animals. Significant differences in health parameters among animals by location and time point were few and included decreased heart rate (F = 12.158, P = 0.001), increased lactate (F = 6.838, P = 0.012), and increased low-density lipoproteins (F = 19.961, P = 0.000) in touch pool animals over time. Based on these results, cownose rays inhabiting a touch pool exhibit and an off-exhibit system remained in comparable planes of health based on routine diagnostic modalities with few differences in measured health parameters.