Pregnancy termination in a mare with hydroallantois*

We describe the successful management, resolution, and subsequent return to breeding of a mare with hydroallantois. A 14-year, American Quarter Horse mare in late pregnancy was referred for marked abdominal distention with a history of treatment for placentitis. Physical examination findings were consistent with hydroallantois. It was decided to terminate pregnancy. During fetal delivery, dystocia was diagnosed and corrected under field anesthesia; recovery was uneventful. Mare conceived the following season and delivered a healthy filly.