Document: Article

Abstract: Pregnancy toxemia is known from terrestrial mammals such as sheep and goats in which late-term twin-pregnant animals may enter a state of negative energy balance with compromised glucose homeostasis. Twin pregnancy is rare in seals, and pregnancy toxemia is undescribed. Herein, we describe a case from an almost 17-year-old harbor seal (Phoca vitulina, Linnaeus, 1758) raised in captivity. The seal died in stage 1 of labor after having experienced a 7- to 14-day period in which it refused to eat, but without any further clinical signs observed. The carcass was CT-scanned and necropsied. The most striking necropsy findings were a late-term twin-pregnant uterus that occupied most of the abdominal space, an abundant amount of fat, compressed and empty stomach and intestines, and diffuse hepatic steatosis. The imaging and necropsy findings indicate that the seal may have died as a result of pregnancy toxemia. As an incidental finding, a well-calcified os cordis was observed with CT, which may be due to the seal’s advanced age. This case thus represents three rarities: twin pregnancy, suspected pregnancy toxemia, and cardiac bone.

Key Words: pregnancy toxemia, labor, aquatic mammals, harbor seals, Phoca vitulina, os cordis, twins

DOI: https://doi.org/10.1578/AM.51.3.2025.276

Page Number: 276-280