The use of ultrasound investigation to identify lines along sea turtle intestinal tract and evaluation of the correlated damages

Accidental hook and line ingestion can cause serious damages to the digestive tract of sea turtles, representing one of the most frequent problems to be faced during their care and rehabilitation. Radiographic examination easily identify hooks, but lines can not be detected as they are radiolucent, limiting the ability of diagnosing their presence, as to evaluate their extension into the digestive canal. And even if the presence of a line is evident because it protrudes from the mouth or the cloaca, it’s not possible to detect any injury caused to the intestinal walls, evident only during surgery. In this study two juvenile loggerhead sea turtles (Caretta caretta), with a line coming out from the cloaca, underwent to ultrasound examination. X-rays had shown a hook lodged into the wall of the cervical esophagus. The ultrasound scans were performed through the cervicobrachial, axillary and prefemoral right and left acoustic windows. The transducer was oriented parallel to the plastron with cranial marker to obtain longitudinal scans , for transverse scans the transducer was rotated 90° anticlockwise with dorsal marker. More diagnostic significant images and movies were obtained by ultrasound scans through the right acoustic prefemoral window. In both cases, it was evident the presence of an abundant amount of particulate fluid in the coelomic cavity. In one turtle it was possible to explore a long tract of the small intestine that showed irregular and tortuous course, with a plicate pattern and a linear intraluminal shadow highly reflective, with a distinct posterior acoustic shadow, compatible with a packaging intestinal loop. The stratigraphy of the intestine showed normal conditions, but the luminal contents of the loop were not detectable for their stretch around the mesentery. In the other case there was a reflective linearity in the coelomic cavity, with a weak posterior acoustic shadow. Moreover, it was detectable a clear dissection of the intestinal wall, small tears and alteration of the intestinal tract stratigraphy. In both cases, the exposure of the intestine during surgery has revealed the extension of the intestinal walls alterations and the severity of injuries, reflecting what was detected by ultrasound examination and confirming the authors’ opinion. Ultrasound examination may provide a valuable support in assessing the extention and severity of digestive tract lesions, caused by the tension of ingested lines. This valuable diagnostic ability has a real important prognostic value, allowing a better adequate planning of surgery.