Yohimbine, 4-aminopyridine, and a combination of the 2 drugs were studied t
o assess their potential as antagonists to xylazine in goats. Twenty-four s
mall East African goats were divided randomly into 4 groups of 6 goats each
in a placebo-controlled study. They were all treated with intramuscular xy
lazine at 0.44 mg/kg. At the time of maximum sedation, sterile water was ad
ministered intravenously to the control group, 0.15% 4-aminopyridine at 0.4
mg/kg to Group 2, 0.1% yohimbine at 0.25 mg/kg to Group 3, and the combinat
ion of the 2 drugs at the same dose rates to Group 4. The yohimbine/4-amino
-pyridine combination was also used to antagonise xylazine at 0.88mg/kg in
6 goats. The heart rate, respiratory rate and rate of ruminal movements, th
e pedal and palpehral reflexes as well as the reaction to noxious stimuli,
the standing time and the total recovery time were established and evaluate
d to assess the effects of the treatments. The drugs reversed the xylazine-
induced decrease in the heart rate, respiratory rate and rate of ruminal mo
vements, and also rapidly restored the reflexes as well as the reaction to
noxious stimulation. In addition, they significantly (P < 0.05) decreased t
he mean standing time. The mean total recovery time was decreased significa
ntly (P < 0.05) by 4-aminopyridine and the yohimbine/4-aminopyridine combin
ation, but non-significantly (P <greater than> 0.05) by yohimbine. No relap
se in sedation occurred. Overall, the combination of yohimbine and 4-aminop
yridine produced better responses than the individual drugs, and may theref
ore be used for rapid reversal of xylazine-induced sedation in goats. Yohim
bine or 4-aminopyridine may also be useful for this purpose but recovery ma
y be prolonged.