A 5-year-old Quarter Horse mare was examined at our university veterinary teaching hospital in March because of a suspected uterine prolapse of 24-hours' duration. The mare had been bred the preceding April and was confirmed pregnant on the basis of results of transrectal palpation and ultrasonography 15 days after ovulation. No other pregnancy evaluations were performed, and there was no history of an abortion or parturition.
Initial examination at the time of admission revealed that the mare was bright, alert, and responsive. Although the rectal temperature was slightly increased (38.5°C [101.3°F]), results for the remainder of the vital indices