Ultrasonographic findings associated with failed pregnancy in the bottlenose dolphin (Tursiops truncatus)

Reproductive success is a critical component of the care of bottlenose dolphins (Tursiops truncatus) in managed care facilities and is vital in sustaining free-ranging dolphin populations. Despite well-established breeding programs with high reproductive success rates, pregnancy failures still occur in managed care just as they do in free ranging dolphin populations. The purpose of this longitudinal study was to report ultrasound measurements and descriptive findings correlated with unsuccessful pregnancies. From 1996-2019, serial ultrasonographic evaluations of 16 dolphins in managed care were performed over 22 pregnancies. A total of 296 ultrasound exams were conducted, including parameters such as fetal biparietal diameter (BPD), thoracic width, thoracic height, aortic diameter, blubber thickness, and uteroplacental thickness.