Gonadectomy in Raccoons: Anesthetic and Cardiorespiratory Effects of Two Ketamine-Based Pre-Anesthetic Protocols before Sevoflurane-Sufentanil

SIMPLE SUMMARY: Raccoon (Procyon lotor) is a non-indigenous wildlife species originating from America which was introduced to Europe in the twentieth century. Raccoons are potential vectors of many diseases that can threaten human and domestic animals’ health. The Northern raccoon is listed within the worst 100 invasive alien species in Europe and since 2004 it has also been introduced to northern Italy. Containment, including birth control and eradication have become crucial steps to preserve and maintain autochthone biodiversity. The aim of this study was to find two anesthetic drug combinations suitable for a safe chemical immobilization and to compare them for qualitative anesthetic effects and influence on vital clinical parameters. The procedure was required to allow a safe handling of wild raccoons, confiscated from northern Italy and referred to the veterinary teaching hospital for gonadectomy, microchip application and subsequent re-release into a protected area. ABSTRACT: Nineteen raccoons were enrolled in this study. The aim was to evaluate and compare the quality of anesthesia and the cardiorespiratory effects following treatment with a ketamine-based combination with either dexmedetomidine (KD group) or midazolam (KM group) in raccoons undergoing ovariohysterectomy/orchiectomy. General anesthesia was maintained with sevoflurane in oxygen and sufentanil infusion. The time required to approach the animals was similar among groups resulting in a median of 5 min after IM injection. Animals in group KD were scored with greater myorelaxation (p < 0.01) and easier intubation (p < 0.05). Moreover 70% of them did not require other drugs for tracheal intubation unlike animals in group KM, which required propofol in 100% of cases. After intubation and connection to the breathing circuit, physiological parameters were monitored continuously and recorded every 5 min. Sevoflurane requirements were lower in group KD than KM (p = 0.005). Blood pressure was maintained within physiological ranges in both groups but with higher values in group KM (p < 0.05). Mild respiratory depression occurred during surgery and animals in group KM showed greater respiratory acidosis (p < 0.05). Recovery was smooth and uneventful in all animals. Both anesthetic protocols can be recommended for safe anesthesia in wild raccoons.