Abstract
Abdominal ultrasonography was performed in six healthy adult brown howler monkeys Alouatta fusca and the normal ultrasonographic anatomy of the liver, gallbladder, stomach and urinary tract described for the first time. Findings were compared with post-mortem studies. The renal cortex was isoechoic to the spleen and isoechoic or hyperechoic to the liver. Kidney length and renal arterial resistive index, systolic and diastolic velocity were calculated. The liver showed a homogeneous hypoechogenic echotexture. The aim of this study was to describe the normal abdominal viscera echoanatomy providing information of normal abdominal anatomical structures in the howler monkey.