Abstract
Over the course of a week, an adult female Steller sea lion, Eumetopias jubatus, in late pregnancy displayed increasing degrees of agitation and inappetance, behaviors consistent with imminent labor and parturition. Following diagnosis by ultrasound in Dec 2009, her health and pregnancy was monitored by weekly veterinary exams under behavioral control and bi-monthly exams while anesthetized. She was last examined 4 May 2010. Findings from that exam and throughout her pregnancy were consistent with examinations from prior years and did not suggest major health problems. Round the clock observation was initiated as the estimated parturition day approached and normal fetal movement was regularly observed. On the morning of 18 June 2010, staff noted fetal movement. That evening she appeared to fall asleep following a bout of activity but was unresponsive when approached minutes later and was dead. An emergency C-section was performed but the fetus had also expired and necropsies took place the following day. On gross examination of the adult, sclera and mucus membranes were icteric. The pancreas contained extensive nodular masses with necrotic cores which on histopathology were described as hyperplastic nodules as well as invasive and metastatic pancreatic adenocarcinoma. Additional findings considered secondary to the neoplasia included pancreatitis, bile duct obstruction, hepatitis, and hepatic encephalopathy. No significant pathology was noted in the fetus; however, it was larger than expected and the placenta had areas of premature separation which presumably contributed to the death of the fetus.
Previous reports of neoplasia in this species in the wild include uterine fibroleiomyoma, palpebral neoplasia, probable fibroma, and possible fibrosarcoma.1,2 Neoplasia in this species in captivity include oral squamous cell carcinoma (Haulena, personal communication), metastatic neuroendocrine carcinoma of the thyroid gland, lymphoma (Tuttle, personal communication), and metastatic pulmonary adenocarcinoma.3
Acknowledgements
The authors thank the husbandry, veterinary, and research staff members at the Alaska SeaLife Center who provided care for and assisted with the necropsy of Kiska, the Steller sea lion in this report.
References
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2. Zabka TS, Gulland FMD, Buckles EL, Nayden D, Lowenstine LJ. Neoplasia in a stranded Steller sea lion, Eumetopias jubatus, in Northern California. In: Proceedings IAAAM 32nd Annual Conference, Tampa, FL, 2001.
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