Intravenous ketamine-xylazine anesthesia through intermittent bolus infusion for surgical suitability in mongrels

Abstract

An experimental study aimed at finding physiological effects, optimal dosage regimen, and assessing surgical operation suitability was organized in 4 females and 4 males’ mongrels using ketamine – xylazine combination. It was planned into 2 phases; the first was to obtain physiological effects and optimal dosage regimen and the second to achieve surgical operation’s suitability by carrying out ovariohysterectomy, enterotomy, gastrotomy and femoral fracture repair. In phase one, dogs were organized into protocol A, B, C each protocol having 1 male and 1 female dogs with varying dosage regimen. A (5 mg/kg ketamine and 2 mg/kg xylazine; 1.25 mg/kg ketamine and 0.5 mg/kg xylazine) B, (2 mg/kg ketamine and 1mg/kg xylazine; 3.333 mg/kg ketamine and 0.333 mg/kg xylazine) C, (22 mg/kg ketamine administered to effect and 1.1mg/kg xylazine as a bolus before ketamine; 5.5 mg/kg ketamine and 0.55 mg/kg xylazine) for induction and maintenance of anesthesia, respectively. In phase 2, the same dogs were grouped into W, X, Y with additional 2 dogs which were not used in phase 1. W, had 2 female dogs for ovariohysterectomy; X, had 1 male and 1 female dogs for gastrotomy and enterotomy, Y had 1 male and 1 female dogs for femoral fracture repair. All dogs exhibited a non-significant increase in rectal temperature. Protocol A and B showed a non-significant decrease in heart rate while C had an increase. Dysrhythmia, bradycardia was also noted. Respiratory rate decreased in all protocols. Pedal reflex was of grade 0. Anesthesia was adequate with quick onset in all protocols; smooth induction, recovery with no salivation and convulsion in A and B while C showed convulsion signs. Palpebral reflex remained sluggish. Protocol A had comparatively better results to B and C. 1 dog died from protocol B at 107th minutes. Protocol A was the most suitable for surgical operations. However, this study did not cater for effects in other breeds of dogs, biochemical and hematological parameters.