Hematologic and plasma biochemical prognostic indicators for stranded free-ranging phocids presented for rehabilitation

This retrospective study used data obtained from medical records of 530 stranded free-ranging harbor (Phoca vitulina), grey (Halichoerus grypus), harp (Pagophilus groenlandicus), and hooded seals (Cystophora cristata) presented to the Marine Mammal Stranding Center in Brigantine, New Jersey from January 1998 through December 2016. The objective was to identify hematological and plasma biochemical parameters of seals at time of presentation that were associated with successful rehabilitation and with duration of hospitalization using univariate and multivariate logistic regressions. At presentation, animals that subsequently survived rehabilitation had greater alkaline phosphatase activity and absolute lymphocyte and total calcium concentrations and lower blood urea nitrogen, sodium, chloride, phosphorus, and total bilirubin concentrations and lower aspartate aminotransferase and alanine aminotransferase activities than animals that eventually died or were euthanized while under care. Results suggest that young, actively growing animals are more likely to survive rehabilitation and that bloodwork consistent with dehydration, systemic disease, and exhaustion are negative prognostic indicators. These results provide prognostic indicators that may aid clinical decision-making for seals presented for rehabilitation.