Determination of the Main Reference Values in Ultrasound Examination of the Gastrointestinal Tract in Clinically Healthy Bottlenose Dolphins (Tursiops truncatus)

The purpose of this work is to evaluate the characteristics of the gastrointestinal (GI) tract of the bottlenose dolphin (Tursiops truncatus) through ultrasonography in clinically sound individuals. The animals were considered healthy based on physical examination, laboratory evaluation (complete blood count and serum chemistry, proteinogram, and fecal analysis), and histological assessment of the mucosa of the proximal gastric chambers. Biopsies were performed by endoscopy. Pregnant animals were not considered. We defined the following ultrasonographic parameters: (1) most useful acoustic windows for the examination of forestomach, fundic stomach, pyloric stomach and bowel; (2) a consistent and standardized method to measure the entire wall thickness in forestomach, fundic stomach, pyloric stomach, and bowel; (3) the normal ultrasonographic appearance of forestomach, fundic stomach, pyloric stomach, and bowel; and (4) the normal peristalsis of forestomach, fundic stomach, pyloric stomach, and bowel. Statistical analysis of the data, collected through ultrasonography of 30 different healthy individuals, permitted the determination of a preliminary reference interval of the GI tract for healthy animals. This study expands the present knowledge of baseline values for ultrasonography of the GI tract in bottlenose dolphins, providing additional relevant data and allowing the clinician the possibility to routinely and non-invasively evaluate a bottlenose dolphin's gastric health more extensively.