Hydrallantois was diagnosed in a 5-year-old Toggenburg doe. Clinical signs included bilateral abdominal distention, anorexia, and recumbency. Ultrasonographically, excessive fluid and live fetuses were detected in the uterus. At the time of cesarean section, the fluid (approx 12 L) was determined to be in the allantoic cavities; concentrations of electrolytes in the fluid were similar to concentrations in allantoic fluid from cows with hydrallantois. Two viable fetuses and 1 nonviable fetus were delivered. The doe retained its placentas for 60 hours, but made a good recovery. Hydrallantois should be considered in the differential diagnosis of abdominal distention in caprine does in late gestation.