Use of the combination of xylazine, ketamine and butorphanol as premedication to enhance sedation and decrease thiobarbital requirements in female dogs undergoing ovariohysterectomy

Abstract

Ovariohysterectomy is a very common surgery in hospitals and veterinary clinics and is also the most common procedure in shelters, like other surgeries, it requires an adequate anesthetic protocol, which includes a correct premedication avoiding the adverse effects derived from the use of these drugs. - Objective: The aim of this study is to compare the effects of butorphanol in combination with xylazine and ketamine to enhance sedation and reduced the thiobarbital requirement. This study was designed to assess anesthetic and analgesic effects during pre-anaesthesia and to analyze cardiopulmonary and analgesic effects as well as anesthesia depth. - Materials and Methods: This study was carried out using 24 females dog from the Insular of Gran Canaria Shelter. All the animals were selected without distinction of race, age, size, or weight and randomly assigned in 2 groups, each group used two alpha 2 adrenergic drugs in combination with or without butorphanol, group A (ketamine-xylazine), group B (ketamine-xylazine-butorphanol). Sedation scales and systematic recording of vital signs were recorded in all groups. Anesthetic induction was performed with thiopental, maintenance with isoflurane, and local anesthetic (bupivacaine). Was also included in the anesthesia protocol for both groups. - Results: All the animals of study were surgically managed without complications and recovered properly. The results obtained were analyzed in a comparative study between both groups, using for some variables a mixed linear model and the Wilcoxon method for others. In general, group GB showed better results in sedation level, thiobarbital requirement, recovery and Glasgow scale. - Conclusion: The use of butorphanol combined with Xylazine, Ketamine and bupivacaine (Group B) showed a better quality of sedation and recovery and values for the Glasgow scale although this difference was not statistically significant compared with the group GA. The addition of Butorphanol to the standard protocol GB showed the lowest thiobarbital requirement being this difference statistically significant compared to the Group A where Butorphanol was not included.