Comparative study between ketamine-S-dexmedetomidine and ketamine-S-midazolam-methadone in the anesthesia of capuchin monkeys (Sapajus apella)

ABSTRACT: Anesthetic protocols have been developed to obtain the most effective and safe association in wildlife. This study compared the anesthetic effects and cardiorespiratory parameters of ketamine-S (+) (10 mg/kg)/dexmedetomidine (0.020 mg/kg) (KD ) and ketamine-S (+) (10 mg/kg)/midazolam (0.5 mg/kg)/methadone (1.0 mg/kg) (KMM ) in capuchin monkeys (Sapajus apella). Eight capuchin monkeys were randomly assigned to KD (n = 4) or KMM (n = 4) to evaluate induction, immobilization, and recovery scores, heart and respiratory rate parameters, besides systolic, mean, diastolic arterial pressure and arterial blood gas. There was no difference (P = 0.56) in the quality of induction, immobilization, and anesthetic recovery between the protocols. The time for anesthetic induction was 4 ± 1 min in the KD group and 5 ± 1 min in the KMM group, and these values were statistically equal (P = 0.28). The mean immobilization time in the KD and KMM groups were 35 ± 13 and 33 ± 15 min, respectively. Heart rate was lower in animals in the KD group (P < 0.001), while respiratory rate (P = 0.03), and mean blood pressure (P = 0.046) were higher than that of the animals in the KMM group. Respiratory acidosis occurred in the KMM group, with lower pH (7.25±0.047; P = 0.0055) and higher pCO2 (51 ± 6;mmHg; P = 0.008). Both protocols exhibited good induction quality, immobilization, and anesthetic recovery, despite cardiorespiratory and blood gas alterations observed, which warrants monitoring of cardiorespiratory variables during KD or KMM chemical restraint.

Individualized Target Training Facilitated Transfer of Group Housed Capuchin Monkeys (Sapajus apella) to Test Cubicles and Discrimination of Targets on Computer Touch Screens

Animals in captivity often experience fear, anxiety and aggression during non-voluntary procedures, leading to adverse behaviors and ineffective outcomes for both animals and caretakers. Negative reinforcement and punishment, often due to ignorance regarding animal learning, can hurt animal welfare. However, voluntary participation through positive reinforcement training (PRT) can decrease stress related to these procedures and increase desired behaviors. Our goal was to demonstrate the positive effects of “target training” on animal welfare by training 10 captive capuchin monkeys (Sapajus apella) in two experiments designed to facilitate movement from a group home enclosure to a test cubicle. In Experiment 1, each monkey was assigned an individualized target (a unique shape/color combination). In daily training sessions, the animal was rewarded with a click-sounding stimulus and a food reinforcer for (a) touching the target, (b) following the respective target into a test cubicle, and (c) touching progressively smaller targets until progressing to digitized images on a computer touch screen. All 10 animals learned to approach and touch their individual physical target in one or two sessions and were able to successfully transition this behavior to an image of their target on a touch screen, although they made more errors with the touch screen. In Experiment 2, the animals were presented with other animals’ targets and novel targets. The seven animals in this experiment all touched their target at higher-than-chance rates in Trial 1 without explicit discrimination training, but only five reached the learning criteria for the task (>83% correct for three consecutive testing days. These results demonstrate that target training can make voluntary movement from group housing to test cubicles easier and benefit future animal care and procedures.