Abdominal ultrasonographic evaluation of the urinary tract, adrenal glands, spleen, hepatobiliary, and gastrointestinal tract in juvenile eastern grey kangaroos (Macropus giganteus)

Abstract

The purpose of this prospective and anatomic study was to describe the ultrasonographic anatomy of the kidneys, urinary bladder, adrenal glands, spleen, liver, gall bladder, and gastrointestinal tract in healthy juvenile eastern grey kangaroos (Macropus giganteus). As ultrasonographic descriptions are lacking in marsupial species, it was also conducted to develop a systematic approach for abdominal ultrasonographic evaluation in the kangaroo and to provide preliminary quantitative and qualitative references. Ten macropod cadavers (eight eastern grey kangaroos and two swamp wallabies (Wallabia bicolor)) were used for initial dissections and preliminary ultrasonographic examinations. Seven eastern grey kangaroos (four females and three males; mean mass 18 kg (±4.5)) were ultrasonographically examined under heavy sedation in lateral recumbency. The gaseous forestomach occupied a large proportion of the entire abdomen ultrasonographically; therefore, the majority of cranial landmarks were based on an intercostal approach comparable to a deep-chested dog. Compared to domestic species, ultrasonographic differences in anatomy include the forestomach, hindstomach, liver orientation, distinguishable adrenal glands, splenic branching, and epipubic bones, all of which were described. The study was limited by the small sample size (7) and weight range (14-25 kg). The systematic approach and description of the normal ultrasonographic anatomy of the abdominal organs in the eastern grey kangaroo should provide a foundation for the ultrasonographic diagnosis and interpretation of abdominal disease in this species.