Guaiphenesin-ketamine-xylazine infusion to maintain anesthesia in mules undergoing field castration

Abstract

BackgroundIn order to determine whether a combination of guaiphenesin, ketamine and xylazine can induce safe and satisfactory anaesthesia in mules undergoing field castration, eight healthy adult intact male mules were employed. They were premedicated with intravenous (IV) xylazine (1.3 mg/kg); an additional dose of xylazine (0.3 mg/kg IV) was administered in case of inadequate depth of sedation. Anaesthesia was induced with IV thiopental (6 mg/kg). The quality of sedation and induction was recorded. Anaesthesia was maintained with an infusion of guaiphenesin (50 mg/mL), ketamine (2 mg/mL) and xylazine (1 mg/mL) (GKX). The spermatic cord of each testis was infiltrated with 5 mL of 2% lidocaine. During anaesthesia heart rate (HR), respiratory rate (RR), rectal temperature (RT) and haemoglobin oxygen saturation (SpO2) were measured every 5 min. The data were analysed with simple one-way analysis of variance (ANOVA). A P value < 0.05 was considered statistically significant. Time of anesthesia, time of surgery and time of recovery were recorded.ResultsOnly one mule required an additional dose of xylazine to achieve a satisfactory depth of sedation. Thiopental at the dose of 6 mg/kg IV resulted in smooth induction and lateral recumbency in all animals. GKX provided adequate anaesthesia to perform castration in all mules. Muscle relaxation was deemed adequate and physiological variables remained stable and within references values during the anaesthesia and did not change in response to surgical stimulation. Time (mean ± standard deviation) from the end of the infusion to sternal recumbency and time from sternal recumbency to standing were 27.7 ± 4.6 and 30.1 ± 7.7 min, respectively.ConclusionsThe combination of xylazine, thiopental and GKX provides satisfactory short-term anaesthesia in mules undergoing field castration.

Analgesic and Sedative Effects of Epidural Lidocaine-Xylazine in Elective Bilateral Laparoscopic Ovariectomy in Standing Mule Mares

“…Previous similar studies on mules and donkeys considered adequate a sample of six animals [ 22 , 26 , 27 ]; therefore, a total of 8 was used to carry out the present study with relevant and encouraging results, although in a small group of animals undergoing surgery. As performed in a previous study, the method used to evaluate the weight of the mules was extrapolated from horses and therefore may not be entirely appropriate for use in this species [ 21 ].…”

“…Mules were premedicated with 0.05 mg/kg acepromazine (Prequillan ® , Fatro, Italy) IM and after 15 min 1.3 mg/kg of xylazine (Rompun ® ; Bayer, Italy) and 0.02 mg/kg of butorphanol (Dolorex ® , Animal Health, Milan, Italy) were administered IV. Depth of sedation was evaluated before epidural administration using a 4-point sedation scale from Vullo et al, 2017 [ 22 ] ( Table 1 ). Additional xylazine (0.3 mg/kg IV) was administered when the mules were poorly sedated (score 0).…”

“…Sedation thereafter was maintained by a constant rate infusion (CRI) of 0.6 mg/kg/h of xylazine that was started when the degree of sedation was considered adequate (score 2 or 3). [22]). The mules' eyes were covered with a drape and cotton wool balls were placed within the external ear canals to minimize visual and auditory stimulation, respectively.…”

“…Scoring system used to assess depth of sedation in 8 mules before ovariectomy (fromVullo et al, 2017 …”

Anesthesia, Sedation, and Pain Management of Donkeys and Mules

“…This study is further described in the section on propofol. Vullo and colleagues 24 described a G-K-X anesthesia maintenance protocol in mules, which, compared with the G-K-X mixture evaluated by Taylor and colleagues 7 in donkeys, required an increase in xylazine dose from 0.5 mg/mL to 1.0 mg/mL.…”