Comparison of three different sedative-anaesthetic protocols (ketamine, ketamine-medetomidine and alphaxalone) in common marmosets (Callithrix jacchus)

Abstract

BackgroundHandling of common marmoset (Callithrix jacchus) usually requires chemical restraint. Ketamine has been associated with muscle damage in primates, while common marmosets, compared to other primates, additionally display an exceptional high sensitivity to ketamine-associated side-effects. Notably, muscle twitching movements of limbs and hands, and a marked increase in salivation are observed. We investigated two alternative intramuscular (i.m.) immobilisation protocols against ketamine (50 mg/kg; protocol 1) in a double-blind randomised crossover study in ten healthy adult common marmosets for use as a safe reliable, short-term immobilisation and sedation. These protocols comprised: alphaxalone (12 mg/kg; protocol 2) and 25 mg/kg ketamine combined with 0.50 mg/kg medetomidine (reversal with 2.5 mg/kg atipamezole; protocol 3A). Following completion and unblinding, the project was extended with an additional protocol (3B), comprising 25 mg/kg ketamine combined with 0.05 mg/kg medetomidine (reversal with 0.25 mg/kg atipamezole, twice with 35 min interval).ResultsAll protocols in this study provided rapid onset (induction times <5 min) of immobilisation and sedation. Duration of immobilisation was 31.23 ± 22.39 min, 53.72 ± 13.08 min, 19.73 ± 5.74 min, and 22.78 ± 22.37 min for protocol 1, 2, 3A, and 3B, respectively. Recovery times were 135.84 ± 39.19 min, 55.79 ± 11.02 min, 405.46 ± 29.81 min, and 291.91 ± 80.34 min, respectively. Regarding the quality, and reliability (judged by pedal withdrawal reflex, palpebral reflex and muscle tension) of all protocols, protocol 2 was the most optimal. Monitored vital parameters were within clinically acceptable limits during all protocols and there were no fatalities. Indication of muscle damage as assessed by AST, LDH and CK values was most prominent elevated in protocol 1, 3A, and 3B.ConclusionsWe conclude that intramuscular administration of 12 mg/kg alphaxalone to common marmosets is preferred over other protocols studied. Protocol 2 resulted in at least comparable immobilisation quality with acceptable and less frequent side effects and superior recovery quality. In all protocols, supportive therapy, such as external heat support, remains mandatory. Notably, an unacceptable long recovery period in both ketamine/medetomidine protocols (subsequently reversed with atipamezole) was observed, showing that α-2 adrenoreceptor agonists in the used dose and dosing regime is not the first choice for sedation in common marmosets in a standard research setting.

Chemical immobilization of captive Cougars Puma concolor (Linnaeus, 1771) (Carnivora: Felidae) using a combination of tiletamine-zolazepam, ketamine and xylazine

“…The dosage of tiletaminezolazepam used in this study was below the dosages recommended for domestic cats (6-15.8 mg/kg) when used as a sole drug (Branson 2001;Pawson & Forsyth 2008) and near the lower limit of the recommended dosage range for large felids (1.6-11 mg/kg) (Gunkel & Lafortune 2007) when used as a sole drug. As the dosages of xylazine and tiletamine-zolazepam used in our study were both low, their effects on the overall blood pressure profile cannot be determined.…”

“…Blood pressure of domestic cats immobilized with tiletamine reached their minimum level 30 minutes after injection and returned later to their basal values (Branson 2001).…”

“…The quality of the anesthesia was given a numerical score from 1 (good) to 3 (unsatisfactory) as described by Bakker et al (2013). The scoring criteria are presented in detail in Table 1.…”

“…At minute 25 of the immobilization period, a slight decrease to 100 beats/min was observed; however, this variation was not statistically significant. Stimulating effects of ketamine and tiletamine on the cardiovascular system might explain the high heart rate observed at the beginning of the immobilization period (Branson 2001;Pawson & Forsyth 2008). The observed decrease in heart rate thus does not represent bradycardia, as bradycardia in large felids is defined as a heart rate below 40-60 beats/min (Gunkel & Lafortune 2007).…”

“…Tiletamine-zolazepam is known to lead to prolonged recovery times in felids, which has been assumed to be a result of its prolonged presence in the blood when compared to dogs (Branson 2001;Gunkel & Lafortune 2007). The difference in recovery times is probably due to the use of tiletamine-zolazepam in this study and the absence of this drug in the study of Curro et al (2004).…”