Retrospective preliminary evaluation of dexmedetomidine-ketamine-midazolam chemical immobilization in pumas (Puma concolor)

Due to their wild nature, chemical immobilization of pumas is necessary for safe clinical management. However, literature on the chemical immobilization of pumas remains scarce, and few pharmacological combinations have been used, including tiletamine-zolazepam, ketamine and xylazine, or detomidine and ketamine, or medetomidine and ketamine [1,2]. The combination of ketamine and an alpha2- agonist with midazolam has not been described in pumas. However, anesthetic mixture including midazolam have been shown to provide cardiovascular stability and uneventful recovery in Panthera tigris [3]. The aim of this retrospective study is to evaluate the clinical effects following the intramuscular (IM) administration of dexmedetomidine, ketamine, and midazolam in eight pumas (Puma concolor) undergoing clinical or surgical procedures performed under field conditions or at the veterinary teaching hospital of the University of Padova. Animals included 4 males and 4 females, with a median age of 7 years (range: 0.3-17) and body weight of 32.5 kg (range: 8-55). Dexmedetomidine (7.8 ± 2.7 mcg/kg), ketamine (2.4 ± 0.2 mg/kg), and midazolam (0.16 ± 0.04 mg/kg) were administered IM via blowpipe darting. Three animals were recumbent but still responsive to stimuli 25 minutes after the injection, and received butorphanol 0.1 mg/ kg IM to facilitate a safe approach. An intravenous catheter was inserted within 17.5 min (range: 11-35) after injection. Anesthesia was maintained with intravenous propofol in all animals, except for one, which was intubated after propofol administration and maintained under volatile anesthesia with isoflurane. Throughout anesthesia, clinical parameters including pulse rate, oxygen saturation, respiratory rate, arterial blood pressure, ECG, end-tidal carbon dioxide, rectal temperature, muscle tone, and palpebral reflex were continuously monitored and recorded every 5 minutes in all animals. Cardiorespiratory parameters remained stable during immobilization and within ranges reported in this animal species. Two pumas received atipamezole 40 mcg/kg IM after the end of the procedures. All animals recovered within 25 ± 5 minutes after the conclusion of clinical or surgical procedures. No peri-anesthetic complications were observed. The combination of dexmedetomidine, ketamine, and midazolam may provide effective and safe immobilization in pumas, ensuring cardiorespiratory stability. However, the addition of butorphanol may be considered to safely approach the animal. [1] Lescano et al. Chemical immobilization of captive Cougars Puma concolor (Linnaeus, 1771) (Carnivora: Felidae) using a combination of tiletamine-zolazepam, ketamine and xylazine. Journal of Threatened Taxa. 6:6659-6667, 2014. [2] Caramalac et al. Efeitos cardiovasculares da medetomidina e cetamina em Puma concolor e tempo de recuperação após aplicação de ioimbina ou atipamezole. Arquivo Brasileiro de Medicina Veterinária e Zootecnia. 72:1666-1674, 2020. [3] Curro et al. Xylazine–midazolam–ketamine versus medetomidine– midazol