Blood chemistry of the brown bear (<i>Ursus arctos</i>) from southwestern Yukon Territory, Canada

Abstract

Blood samples from 22 brown bears (Ursus arctos) were assayed for calcium, phosphorus, glucose, urea, creatinine, uric acid, cholesterol, total protein, albumin, total bilirubin, alkaline phosphatase, lactic dehydrogenase, glutamic–oxaloacetic acid transaminase, sodium, potassium, and chloride.Statistically significant seasonal changes in brown bears included a spring-to-summer decrease of calcium, urea, creatinine, and uric acid and concurrent increases of glucose and potassium. These changes may be related to renal function and seasonal variations in the bear's diet. The only sexual difference was the higher uric acid levels in male brown bears than in females.The blood chemistry of four black bears (Ursus americanus) was similar to that of brown bears except for slightly higher levels of phosphorus, creatinine, uric acid, glutamic–oxaloacetic acid transaminase, sodium, and chloride. Our limited sample of black bears did not allow an investigation of seasonal changes.