Differences in electrocardiographic responses of young and adult Indian sloth bears (Melursus ursinus) to ketamine-xylazine anesthetic combination

The study reports the differences in the electrocardiographic responses of young and adult Indian sloth bear (Melursus ursinus) to ketamine-xylazine anesthetic combination.Moreover, no baseline electrocardiographic data for Indian sloth bears is available in the literature.A twelve-lead standard ECG recorder was used and its electrodes of the electrocardiograph were connected over the olecranon and the patella.The configuration of the R wave was upright in most of the leads in both young and adults while inverted R wave was obtained in both age groups in lead aVR.The PR interval of young sloth bears was recorded as non-significantly (p>0.05)lower than that of adults.The QT interval was recorded significantly (p<0.05)higher in adults than in young sloth bears in all the bipolar and unipolar leads.RR interval in young sloth bears recorded significantly lower values in lead I and non-significantly lower values in the rest of the leads.Lead I and lead II of young sloth bears recorded significantly higher heart rates than adults.The QRS electrical axis ranged from 57 to 131 degrees in young and 66 to 77 degrees in adults.No cardiac distress or arrhythmia was evident from the electrocardiograms and use of ketamine-xylazine anesthetic combination for immobilization of sloth bears during ECG recording can be recommended.The results of the study can be used for ECG interpretation in Indian sloth bears.