Comparative evaluation of propofol alone and along with xylazine or midazolam in healthy dogs

Eighteen adult non-descript healthy dogs were used in three equal groups to evaluate the quality of anaesthesia produced by propofol alone and along with preanaesthetics, xylazine or midazolam. In group I, propofol was used for induction (bolus dose of 5mg/kg b.wt, i.v.) and maintenance (continuous i.v. infusion 0.2 mg/kg/per min) of anaesthesia without any premedication. Whereas in groups II and III, xylazine (2mg/kg b.wt i.v.) and midazolam (0.3 mg/kg b.wt i.m.), respectively, were used as preanaesthetics before propofol administration. Effect on quality of anaesthesia, changes in clinical, haematobiochemical parameters and side effects if any, were noted during the 90 min observation period. Group II registered maximum duration of analgesia (35.62±2.84 min) and recumbency (92.72±5.95 min), whereas the recovery time was 32.07±2.99 min. Haemato-biochemical parameters showed nonsignificant changes in their values during the entire observation period. Common side effects observed were transient apnoea, vomiting, urination, paddling movements, ophisthotonus and salivation, although none of these was clinically significant. It can be concluded that xylazine-propofol anaesthetic regimen (group II) is better than other two anaesthetic regimens due to an early onset, longer duration of analgesia and minimum adverse effects.