Survival versus nonsurvival determinants for neonatal harbor seals.

Of 29 neonatal harbor seals that had been abandoned, separated from their mothers, or stranded in the wild, 22 succumbed during hospitalization at the California Marine Mammal Center in the spring of 1982. Compared with standard reported harbor seal pup measurements, 8 of the nonsurviving pups were premature (ie, creamy-white lanugo coat, early pupping season birthdate, and decreased body size [6 to 10 cm shorter and 2.3 to 4.5 kg less than normal]). The premature pups and the young pups (less than or equal to 10 days old) had at least two of the following findings: jaundice, emaciation, labored respiration, hyperbilirubinemia, hypoglobulinemia, or leukopenia. Most of the nonsurviving pups died within 96 hours after admission. Macroscopic and microscopic findings indicated that a high percentage of these pups had pulmonary congestion and edema (72.7%), alveolar squamous cells/debris (27.3%), and/or congenital cardiac anomalies (ie, patent ductus arteriosus [63.6%] and patent foramen ovale [45.4%]). Two older pups (greater than 10 days old) died from chronic bacterial infections, accompanied by adrenal cortical hyperplasia. The 7 surviving pups had adult spotted pelage, normal body weights (9 to 11 kg), normal globulin concentrations (3.0 to 5.1 g/dl), and normal WBC counts (7 to 9 X 10(3)/microliters) and did not have clinical signs of icterus or respiratory distress.