EVALUATION OF CARDIOLOGIC FUNCTIONS IN CAPTIVE EURASIAN BROWN BEARS (URSUS ARCTOS ARCTOS) IN TURKEY

The aim of this study was to evaluate the cardiac functions in healthy Eurasian brown bears (Ursus arctos arctos) living in a seminatural area during their active season. Twelve clinically healthy brown bears were selected based on their normal physical examination, hematologic, and serum biochemistry results. These bears were divided into two groups based on age; subadult (<5 yr, n = 4) and adult (≥5 yr, n = 8). After the chemical immobilization (ketamine and xylazine), routine clinical and laboratory examinations were performed. Also, cardiologic examinations were performed using electrocardiogram and echocardiogram. There were no significant differences for the clinical parameters between the two groups including for body temperature, heart and respiratory rates, capillary refilling time, and oxygen saturation. The Q, R, and S wave (QRS) complexes and T wave amplitude were higher (P < 0.05) in the subadult group when compared to those of adult bears. Notching of QRS complexes and peaked T wave were also observed in both groups. Left ventricular diameter at systole and diastole in adult bears was wider (P < 0.05) than that of subadult bears. Subadult bears had reduced aortic diameter compared to adult bears (P < 0.05). Doppler variables of mitral, tricuspid, and aortic inflows between groups were similar; however, pulmonary artery variables such as flow velocity integral, mean velocity, and gradient were higher (P < 0.05) in the subadult group. These results suggest that electrocardiographic and echocardiographic parameters should be evaluated based on the age of brown bears.