General anesthesia in Sapajus nigritus (black capuchin)

Background: The black capuccin (Sapajus nigritus) is one of the most abundant primate specimens in Brazil. Among population control techniques, vasectomy can be used once it maintains the animal's leading behavior in the group through hormonal presence, production of spermatogenic series, and copula. However, due to their escape behavior, agitation, in addition to the impossibility of knowing the physiological state of these animals beforehand, their capture poses a considerable challenge. Thus, chemical restraint is indispensable and the use of effective and safe anesthetic protocols to animal integrity is of paramount importance. In this scenario, the present study aims to report the anesthesia of a black capuccin submitted to vasectomy.Case: A 1-year-old male, 1.1 kg monkey (Sapajus nigritus) was admitted at a Veterinary Hospital after being found on the ground in a natural reserve in the town of Assis Chateaubriand, in the west of Parana State. After clinical evaluation, the patient was submitted to vasectomy as a birth control method, before his return to the natural area, which presented overpopulation of the species. After preanesthetic examinations, the animal was considered healthy, and thus, premedicated with the combination of dexmedetomidine (10 μg/kg) and ketamine (10 mg/kg), intramuscularly. Anesthetic induction with propofol was performed to effect. Laringeal desensitization was achieved with 2% lidocaine (2 mg/kg), which allowed orotracheal intubation through direct visualization. Anesthesia was maintained with 1% isoflurane in a 0.5 oxygen fraction and spontaneous ventilation using a non-rebreathing circuit. The spermatic cord and the skin were desensitized with lidocaine (2 mg/kg). During the procedure, the animal was monitored for pulse oximetry, electrocardiogram, systolic blood pressure, body temperature, end tidal CO2 (ETCO2), and end tidal isoflurane. The animal also received 10 mL/kg/h ringer lactate throughout anesthesia and 30 mg/kg ampiciline as prophylactic antibiotic. After the completion of the surgery, inhalation anesthesia was interrupted and the animal was allowed to wake up. Discussion: The combination of 10 µg/kg dexmedetomidine and 10 mg/kg ketamine caused intense muscle relaxation and short-term sedation, which lasted 15 min. Protocol was sufficient for veno puncture and pre-oxygenation, but doses should be increased for longer procedures. Although other authors reported physiologic alterations with higher doses of these drugs, such complications were not observed in the present case. The anesthetic induction was smooth, with no excitement or complications. Propofol was infused at 1 mg/10 s, and a total dose of 10 mg/kg was necessary for induction. This rapid infusion rate could have caused the increase in propofol total dose, as described elsewhere. Propofol and local lidocaine allowed orotracheal intubation with a 2.5 mm uncuffed neonatal tube. During surgery, analgesia was achieved with pre surgical local anesthetic and a single bolus of fentanyl during duct deferens manipulation. During anesthesia, heart rate was maintained between 140 and 170 bpm; systolic blood pressure, between 85 and 110 mmHg; respiratory rate, between 30 and 50 mpm; and ETCO2, between 25 and 30 mmHg. No assistance in ventilation was necessary. The procedure lasted one hour, and extubation occurred seven minutes after the interruption of inhalational anesthetic. Anesthesia and anesthesia recovery occurred without complications, allowing the accomplishment of a short duration surgical procedure. After the post operatory period, the animal was reintroduced to the wild, with authorization of the state environmental agency. In conclusion, low dose dexmedetomidine combined with ketamine is adequate for rapid chemical restraint of black capuccin, and do not cause physiologic alterations during isoflurane anesthesia.