To determine whether anesthesia consisting of sedation induced by intramuscular administration of xylazine hydrochloride and lumbosacral analgesia induced by epidural administration of lidocaine and xylazine is useful for umbilical surgery in neonatal calves.
6 neonatal male dairy calves.
Calves were sedated with xylazine (0.1 mg/kg [0.045 mg/lb] of body weight, IM), and 5 minutes later a 2% solution of lidocaine (0.18 to 0.24 ml/kg [0.08 to 0.11 ml/lb]) and xylazine (0.05 mg/kg [0.022 mg/lb]) were administered into the lumbosacral epidural space. Calves were positioned in dorsal recumbency, and the umbilical structures were resected. Local infusion of lidocaine, cranial to the umbilicus, was required in 5 of 6 calves to provide adequate analgesia. Xylazine sedation was reversed with tolazoline (1 mg/kg [0.45 mg/lb], IV).
Calves maintained adequate cardiac output and oxygen delivery throughout the procedure but were hypotensive. Reversal of xylazine-induced sedation with tolazoline caused transient sinus bradycardia and sinus arrest, accompanied by severe systemic arterial hypotension. All calves regained a suckle reflex within 10 minutes and were able to stand within 90 minutes.
Intramuscular administration of xylazine for sedation and epidural administration of lidocaine and xylazine for analgesia failed to provide satisfactory analgesia for umbilical resection without supplemental local infiltration of lidocaine. The anesthetic protocol is most useful when respiratory compromise or cost are concerns and the surgical procedure can be completed in < 1 hour. Caution should be exercised when tolazoline is administered intravenously to reverse xylazine-induced sedation in calves. (J Am Vet Med Assoc 1999;214:89–95)
Case Description—A 4-month-old Hampshire ram underwent open right inguinal herniorrhaphy and unilateral castration following herniation that developed after a kick injury. Seven months later, the ram was reevaluated because of scrotal swelling of 1 month's duration as well as suspected left inguinal hernia.
Clinical Findings—The ram had marked scrotal swelling. Palpation of the left testicle revealed no abnormalities. Ultrasonographic examination revealed heterogenous tissue within the cranial and medial portions of the scrotum with pronounced accumulation of hypoechoic fluid at the scrotal apex. Examination findings indicated left-sided indirect inguinal herniation of omentum.
Treatment and Outcome—To preserve fertility, left inguinal hernioplasty without castration was performed. The ram was anesthetized and placed in dorsal recumbency, and laparoscopic abdominal evaluation revealed omental entrapment within the left inguinal ring. The omentum was removed, and a polypropylene mesh was secured over the internal inguinal ring with an articulating hernia stapler. Following mesh placement, a dorsally based peritoneal flap was elevated and secured over the mesh repair. The ram recovered well from surgery; there was no repeated herniation following the surgical correction, and the ram was able to breed successfully without complication.
Clinical Relevance—Laparoscopic mesh hernioplasty can be successful in rams with inguinal hernias when preservation of fertility is preferred.