Ultrasonogram of the fetus of Hokkaido brown bear.
Pregnancy diagnosis by the ultrasonogram method was carried out in a captive 13 years old female Hokkaido brown bear. Two fetuses were detected in the left abdomen. The fetus transverse diameter was 5.2 cm and the heart rate was 180 beats/min. Further improvement is necessary to diagnose the number of fetuses by our method, for she gave birth to 3 cubs 4 days later.