title: Effects of intratesticular and incisional local anesthetic administration for castration of alpacas anesthetized with intramuscular ketamine-xylazine-butorphanol.
abstract: OBJECTIVE
  To determine the effects of intratesticular and incisional injection of local anesthetics on response to castration, surgical ease, and recovery in alpacas.
  
  
  METHODS
  Prospective, blinded, randomized, and clinical trial.
  
  
  METHODS
  Intact male alpacas (n = 38).
  
  
  METHODS
  Alpacas were anesthetized with intramuscular butorphanol, ketamine, and xylazine (BKX). Once recumbent, alpacas were instrumented with electrocardiogram, pulse oximeter, oscillometric blood pressure, and capnography. Heart rate (HR), respiratory rate (RR), and blood pressure (BP) were recorded every minute. Treatment drug (lidocaine, bupivacaine, or saline) was infiltrated along the incision and into both testicles followed by a prescrotal closed castration. Timing of major events, presence of movement during the procedure, need for additional anesthesia, and ease of surgery were recorded. Alpacas were administered postoperative oral meloxicam and assessment was made 24 hours after recovery.
  
  
  RESULTS
  Median RR and mean BP (MBP) were lower in the lidocaine compared with the saline treated group. Median RR, HR, and MBP were significantly lower in the bupivacaine group compared with the saline group. Fewer alpacas displayed physical response to surgical stimulus with bupivacaine. No significant differences were found between groups for timing of events, need for additional anesthesia, ease of surgery, or postoperative assessment.
  
  
  CONCLUSIONS
  Intratesticular local anesthetic blunts autonomic response and facilitates castration in alpacas anesthetized with BKX with minimal negative effects. Bupivacaine may have some benefit for local anesthesia during castration compared with lidocaine.
authors.affiliation: William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, California.
authors.forename: Jordan
authors.initials: J
authors.lastname: Nickell
authors.forename: Linda S
authors.initials: LS
authors.lastname: Barter
authors.forename: Julie E
authors.initials: JE
authors.lastname: Dechant
mesh_terms: D000778:Anesthetics, Dissociative / Q000008:administration & dosage; D000779:Anesthetics, Local / Q000008:administration & dosage*; D000818:Animals; D002045:Bupivacaine / Q000008:administration & dosage; D002077:Butorphanol / Q000008:administration & dosage; D002161:Camelids, New World / Q000502:physiology / Q000601:surgery*; D007273:Injections, Intramuscular; D007649:Ketamine / Q000008:administration & dosage; D008012:Lidocaine / Q000008:administration & dosage; D008297:Male; D009919:Orchiectomy / Q000379:methods / Q000662:veterinary; D010147:Pain Measurement / Q000662:veterinary; D011446:Prospective Studies; D014991:Xylazine / Q000008:administration & dosage
chemical_list: D000778:Anesthetics, Dissociative; D000779:Anesthetics, Local; D014991:Xylazine; D007649:Ketamine; D008012:Lidocaine; D002077:Butorphanol; D002045:Bupivacaine