Ultrasonographic features of the platypus abdomen via a limited left pre‐epipubic acoustic window from a series of 54 individuals

INTRODUCTION: There are notable differences between the platypus and common species of domestic mammal in the location and structure of some abdominal organs. The aim of this study was to detail the size, position and relative locations of organs in the left side of the platypus abdomen, to assist evidence-based decision-making in a clinical setting. MATERIALS AND METHODS: Abdominal ultrasonography was performed on 54 wild, adult platypuses (31 males, 23 females) in northwest Tasmania. Examinations were performed under isoflurane anaesthesia, with platypuses in dorsal recumbency, through a 4 × 2 cm acoustic window between the caudal ribs and the epipubic bone. Abdominal organ position and morphometrics were recorded. RESULTS: The right ventral process of the spleen was located directly under the acoustic window in 53 platypuses. The left kidney was always located dorsal to the right ventral process of the spleen and, at least in part, cranial to it in 46 platypuses. The left dorsal process of the spleen was located dorsally. The left testis or left ovary was located caudal or caudoventral to the left kidney and caudal or caudodorsal to the right ventral process of the spleen. DISCUSSION: The described acoustic window on the left ventral abdomen provides good ultrasound access to a number of organs in the left side of the abdomen. The position of the right ventral process of the spleen in most platypuses, directly under this clipped area, makes this structure a good landmark and starting point for ultrasound examination of the other organs imaged.