Detomidine and xylazine, at different doses, in donkeys (Equus asinus)

The effects of detomidine and xylazine in northeasters donkeys were compared. Six animals participated, randomly, of all experimental groups: xylazine 10%, 0.8 mg/kg (xylazine group 0.8 - GX0.8), 1.0 mg/kg (GX1.0) and 1, 2 mg/kg (GX1.2); and detomidine 1%, 0.02 mg/kg (Detomidine group 0.02 - GD0.02), 0.04 mg/kg (GD0.04) and 0.06 mg/kg (GD0.06) intravenous. Heart rate (HR) and respiratory rate (RR), rectal temperature (RT), mean arterial pressure (MAP), blood glucose, sedation, analgesia, ataxia, arrhythmias and urination were monitored. Duration of sedation was greater in the groups in which detomidine was administered. The muzzle-soil distance significantly reduced in all groups five minutes after the sedative administration, remaining smaller for a longer time in the GD0.06. Ataxia in GX1.0 was greater than in GX0.08 and GX1,2, being equivalent to GD0,04 and GD0,06. Analgesia lasted 30 minutes in GD0.06 and 10 minutes in the others. There was reduction of HR in GD0.02 and GD0.04 and atrioventricular block. There was a reduction in TR in GX1,2, GD0.02, GD0,04 and GD0,06. RR decreased in all groups. MAP increased in GD0.02, GD0.04 and GD0.06 five, 20, 30 and 10 minutes after administration of detomidine, respectively. Hyperglycaemia occurred for 120 minutes in all animals receiving detomidine. The frequency of micturition was higher in GD0.06 (2.2 ± 0.8) than in GX0.8 (0.8 ± 0.4). In northern Brazil, detomidine and xylazine promote short duration analgesia and cardiorespiratory alterations, but detomidine causes a greater sedative, hypertensive and hypothermic effect.