Computed Tomography Diagnosis of Pneumothorax and Cardiac Foreign Body Secondary to Stingray Injury in a Bottlenose Dolphin (Tursiops truncatus)
This report describes a fatal stingray interaction with a bottlenose dolphin (Tursiops truncatus) and the use of multidetector computed tomography (CT) imaging for determination of cause of death prior to gross necropsy. An adult male bottlenose dolphin was found deceased in May 2017 and brought to the University of Florida for examination. No external signs of trauma were initially appreciated. CT examination revealed a moderate to severe right-sided pneumothorax and three linear mineral-attenuating foreign bodies, one of which was coursing through the mediastinum and pleural space and lodged within the right atrium of the heart. The foreign objects were identified as stingray barbs on gross examination at necropsy. The basilar aspect of the barb within the heart punctured through the right cranioventromedial lung pleura which showed evidence of focal pleuritis. Histopathologic examination showed pneumonia and a fibrinosuppurative endocarditis with associated heartbase hemorrhage. No clear path of travel for this barb was identified. Bottlenose dolphins and many stingray species share a habitat off the Southeastern United States.1 Interactions are well-documented and injuries sustained can range in severity from incidental to fatal.2,3,4,5,6,7,8,9,10 Barb injuries have also been implicated as a possible cause for vague clinical signs in rehabilitating animals.9 This case illustrates how CT imaging could be an important antemortem screening tool for clinicians working with stranded or rehabilitating wild dolphins. Furthermore, stingray injury should be considered as a differential in cases of dolphin mortalities or strandings even in the absence of external trauma or in those with unexplained clinical signs.
The authors would like to thank Laurie Adler, Mackenzie Russel, Nina Thompson, George H. Burgess, Salvatore Frasca Jr. and Randall Wells for their assistance and expertise with this case. This dolphin originated from Clearwater Marine Aquarium stranding network who have generously supported the post mortem scanning project at UF. Thanks to the CMA veterinary and the rescue team for all of their help and for transporting the animal for scanning.
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