CLINICAL AND CLINICAL LABORATORY CORRELATES IN SEA OTTERS DYING UNEXPECTEDLY IN REHABILITATION CENTERS FOLLOWING THE EXXON-VALDEZ OIL-SPILL

Following the Exxon Valdez oil spill, 347 oiled sea otters (Enhydra lu tris) were treated in rehabilitation centers. Of these, 116 died, 94 w ithin 10 days of presentation. Clinical records of 21 otters dying dur ing the first 10 days of rehabilitation were reviewed to define the la boratory abnormalities and clinical syndromes associated with these un expected deaths. The most common terminal syndrome was shock character ized by hypothermia, lethargy, and often hemorrhagic diarrhea. In heav ily and moderately oiled otters, shock developed within 48 hours of in itial presentation, whereas in lightly oiled otters shock generally oc curred during the second week of captivity. Accompanying laboratory ab normalities included leukopenia with increased numbers of immature neu trophils (degenerative left shift), lymphopenia, anemia, azotemia (pri marily prerenal), hyperkalemia, hypoproteinemia/hypoalbuminemia, eleva tions of serum transaminases, and hypoglycemia. Shock associated with hemorrhagic diarrhea probably occurred either as a direct primary effe ct of oiling or as an indirect effect secondary to confinement and han dling in the rehabilitation centers. Lightly oiled otters were less li kely to die from shock than were heavily oiled otters (22% vs. 72%, re spectively). Heavily oiled otters developed shock more rapidly and had greater numbers of laboratory abnormalities, suggesting that exposure to oil was an important contributing factor.