Physiologic and biochemical effects of subarachnoidally administered xylazine and medetomidine in goats

Clinicophysiological, haematological and biochemical effects of xylazine (0 .05 mg kg(-1)) and medetomidine (0.01 mg kg(-1)) were studied in nine adult goats after lumbosacral subarachnoid administration. The onset of analgesi a by xylazine and medetomidine was observed in 9.11 +/- 1.07 and 8.66 +/- 2 .37 min (mean +/- S.E.), respectively. Both alpha (2)-agonists produced mod erate analgesia of hind quarter, perineum and flank, mild ataxia and sedati on. The duration of analgesia after xylazine administration was 134.44 +/- 8.87 min and that after medetomidine was 158.33 +/- 9.96 min (mean +/- S.E. ). Xylazine and medetomidine induced significant (p<0.05) decrease in heart rate, respiratory rate and hypothermia. Haemoglobin (Hb), packed cell volu me (PCV) and total leukocyte count (TLC) decreased significantly. Changes i n the physiological and haematological parameters were transient in nature. Xylazine and medetomidine produced a significant (p<0.05) increase in crea tinine and glucose levels. However, these parameters fluctuated within norm al range and started to recover within 120 min. However, serum urea nitroge n (SUN), serum chloride, sodium and potassium did not show any significant change. The effects produced by xylazine and medetomidine were however, com parable at these dose levels. The study indicates that xylazine at 0.05 mg kg(-1) and medetomidine at 0.01 mg kg(-1) did not induce any serious altera tion in the physiological, haematological and biochemical parameters and ca n be safely used in inducing hind quarter, flank and perineal analgesia in goats. (C) 2000 Elsevier Science B.V. All rights reserved.