ABSTRACT. We performed a thoracic X-ray examination of 56 Japanese macaques to obtain normal reference values for vertebral heart scale (VHS). Mean VHS was 10.25  0.94v. In males, mean VHS was 10.56  0.73v, with no significant correlation to age or weight. In contrast, mean VHS in females was 9.97  1.03v, and tended to decrease with increasing age and weight. These findings will facilitate the diagnosis of cardiac disease in Japanese macaques in the future.

Japanese macaques bred indoor for laboratory use often show chronic anorexia and intermittent vomiting. In some of our macaques gastric air was observed on physical examination, and we suspected abnormality of gastric motility. We therefore performed contrast radiographic examinations of the gastrointestinal tract without anesthesia of 8 macaques with gastrointestinal symptoms and 9 asymptomatic controls from the same laboratory. Changes of abdominal radiography over time were observed following oral administration of contrast medium. In all control animals, contrast medium had completely passed from the stomach within 150 min after administration. However, all animals with gastrointestinal symptoms retained some contrast medium in the stomach. Gastric emptying time of contrast medium was associated with excessive gastric air in Japanese macaques; therefore, gastric emptying time seems to be associated with decreased gastric motility.