Is Detomidine Suitable for Colic in Horses?

Aims: Use of detomidine, a potent α2 agonist equine sedative and analgesic is still controversial in horses with colic, especially regarding gut motility or re-administration. 

Methods: In order to learn more about induced ileus and re-administration effects, 10 healthy adult horses were administered nasogastric charcoal (1 g/kg bwt) prior to one of 4 sedation protocols, alternatively given to all of them: S1 = no sedation, S2 = 0.02 mg/kg bwt i.v. detomidine, S3 = 0.04 mg/kg bwt sublingual detomidine, S4 = S2+S3, t0+45 min later. Heart rate, sedation and head position (0 to 2), as well as gut motility (abdominal sounds, 0 to 3; auscultation) were recorded every 5 then 15 min for 210 mins. Time for dark faeces (hours) and side effects were also monitored. Wilcoxon signed rank test and t test and were used with P<0.05 regarded as significance. Tested protocols were equivalent for bradycardia.

Results: S2, S3 and S4 provided similar profound sedation. S4 induced a significant longer max-sedation time (200 min vs. 110 min/S2, 140 min/S3) and more sweating. Head raised back to nearly normal position at t210. Gut sounds decreased with all protocols, without any statistical difference, but never disappeared. [...]