Maxillary nerve block technique for molariform extraction in rabbit (Oryctolagus cuniculus): Case report

Abstract

Among unconventional pets, rabbits are often appreciated animals for having a docile temperament. However, its anatomical and physiological particularities predispose to dental disorders, eventually requiring surgical and anesthetic interventions. Considering that there are no reports on the clinical applicability of the maxillary nerve block for surgical procedures in this species, the objective was to evaluate the effectiveness of the technique in a 4-year-old New Zealand rabbit (Oryctolagus cuniculus), weighing 4.1 kg, attended at the Veterinary Hospital of the Federal University of Paraná in march 2022. After clinical evaluation and radiographic examination, retrograde growth was observed and instituted as molariform extraction. As preanesthetic medication, a combination of dexmedetomidine (30 ug/kg), methadone (0.5 mg/kg), and midazolam (1 mg/kg) was administered. Subsequently, anesthetic induction was performed with propofol (3 mg/kg) and its maintenance with isoflurane and propofol. Aiming at preemptive analgesia, maxillary nerve block was performed by anatomical reference with lidocaine hydrochloride without vasoconstrictor (3 mg/kg). During the intraoperative period, physiological parameters such as heart and respiratory rate, systolic, mean and diastolic blood pressure, pulse oximetry, end-expiratory carbon dioxide and rectal temperature were measured and subsequently recorded. Finally, the maxillary nerve block technique proved to be effective for the proposed procedure, since there were no intraoperative parametric changes in nociception. However, broader, controlled studies with a greater number of animals need to be carried out in order to guarantee its indication, as well as further clarifications regarding the applicability in the use of long-acting local anesthetics for postoperative analgesia in this species.