As previously announced, Toto, a Western lowland Western Gorilla at Ueno Zoo, underwent anesthesia for examination due to irregular menstrual bleeding and slight weight loss. The examination results and subsequent progress are reported below.

CT and ultrasound examinations revealed multiple fibroids in the uterine body, but a detailed review of the images suggests that uterine cancer is unlikely. However, due to the lack of suitable equipment for gorillas, an endometrial cytology test could not be performed, and therefore an accurate diagnosis has not been obtained. On the other hand, no abnormalities were found in the cervical cytology test.

Based on the test results, irregular menstruation due to ovarian dysfunction was suspected as the cause of the abnormal bleeding. Therefore, we started administering birth control pills, and the symptoms have now improved. We plan to continue conducting regular health checkups for Toto.

(June 7, 2024)