Sedative and antinociceptive effects of xylazine combined with tramadol or pentazocine in goats

The aim of the study was to evaluate the quality of sedation and analgesia produced by xylazine alone and in combination with tramadol or pentazocine in goats.
Four male adult West African goats weighing 8.5 ± 0.2 kg (Means ± Standard Deviation) were sedated with each of three treatments in a randomized cross over design at one week interval between treatments. Treatments were Xylazine (0.1mg/kg) with normal saline (XYL-SAL); with tramadol (3mg/kg, XYL-TRA) and with pentazocine (2 mg/kg, XYL-PEN). Sedation scores, heart rate (HR), respiratory rate (RR) and rectal temperature (RT) were obtained before drug administration and subsequently at ten -minute intervals.
Onset of sedation were 7.5 ± 0.7 min, 5.8± 1.3 min and 6.3 ± 1.7 min with the XYL—SAL, XYL-TRA and XYL-PEN treatments respectively. Duration of sedation was forty minutes with XYL-SAL and XYL-TRA and 50 minutes with XYL-PEN. Peak sedation occurred between thirty and forty minutes with the three treatments. At peak effect, sedation was mild with XYL-SAL, mild to moderate with XYL-TRA and intense with XYL-PEN but without analgesia.
Heart and respiratory rates fell significantly from baseline values by 10 minutes post drug administration in the goats with the three treatments while rectal temperature remained unchanged. Side effects observed was drooling by all the goats with XYL-PEN and one goat with XYL-TRA. One goat had paraphimosis with XYL-TRA.
It was concluded that addition of pentazocine to xylazine in goats enhanced sedation although without analgesia and provided better sedation quality than addition of tramadol.