USE OF XYLAZINE FOR CAUDAL EPIDURAL-ANEST HESIA IN CATTLE

The effect of epidural administered xylazine was investigated in 10 ma ture Holstein cows (mean age: 5,4 +/- 1,2 years, mean BW: 572 +/- 23 k g): 5 cows were treated with xylazine in a low dose of 0,05 mg/kg body weight, 3 cows in a medium dose (0,07 mg/kg BW) and 2 cows in a high d ose (0,1 mg/kg BW). Xylazine dosages were diluted in sterile saline to a final volume of 5 ml. As a control, lidocain (5 ml of a 2% solution ) was given to 5 cows epidurally. Duration of regional anaesthesia aft er low dose of xylazine (0,05 mg/kg BW) was significant longer (mean: 2,2 hours) compared to lidocain treated cows (mean: 1,1 hour). Regiona l extension of anaethesia was comparable after dosing with xylazine an d lidocain (tail, after, vulva and perineum). All cows remained standi ng, but in xylazine treated cows systemic effects, e. g. mild sedation , decreased heart- and respiratory rates, decreased rumen motility and mild bloat were observed, With increased dosages of xylazine a prolon gation of epidural anaethesia up to 3 hours was achieved, but regional extension of this effect remained nearly unchanged. With increased xy lazine dosages, cows showed markable sedation and ataxia and sternal r ecumbency were induced.