Abstract

A chute conditioned 2-year-old reticulated giraffe (Giraffa camelopardalis reticulata) was castrated using standing sedation and an EZE bloodless castrator.¹ The decision to castrate this young male giraffe was based on the inability of the Cheyenne Mountain Zoo to accommodate two adult male giraffes in their current enclosure. This 2-year-old bull was beginning to spar and exhibit aggression with the adult bull in the giraffe herd (his sire). Shipping this young male was not an option at the time.

Among the anesthetic challenges facing zoo veterinarians, giraffe anesthesia is considered to have a historically high mortality rate associated with it.² For this reason, we decided to perform the castration using a standing sedation protocol with the alpha-adrenergic agonist xylazine. Before attempting this procedure, the keeper staff intensely chute conditioned this giraffe over a period of several weeks. The conditioning was gradual, and by the end of the conditioning the giraffe was allowing the placement of bellybands and a quick release head halter. The decision to use a banding castrator rather than performing an open castration was based on the temperament of the giraffe and the limited access to the scrotum and testes in the standing position.

Methods

A 2-year-old male reticulated giraffe weighing 632.0 kg was placed in a box-type chute with removable side panels. Two 6-inch-wide nylon mesh straps were placed in a ventral abdominal position, one just caudal to the axilla, and one just proximal to the scrotum. The giraffe was given 100 mg of xylazine IM (Rompun, Miles Laboratories) and within 15 minutes the giraffe was so sedate that he began to buckle on all four limbs, using the bellybands to support most of his weight. The scrotum was then prepared aseptically for the castration. Fifteen milliliters of buffered lidocaine (1:1 dilution of 2% lidocaine and 8.4% sodium bicarb) was infused by injection in and around the proximal portion of the scrotum and spermatic cord. Sedation was profound enough at that time to cause laxity of the giraffe’s head and neck. At this time, a quick release halter was placed on the giraffe to support his head and neck, and a nasal cannula was placed providing 100% oxygen supplementation, heart rate and oxygen saturation were monitored via pulse oximetry. The scrotum and testes were manually isolated from the body wall and two rubber-castrating bands were placed as tightly as possible between the testes and the body wall. Blood was drawn for a CBC and serum chemistry panel; and the following medications were given: 600 mg of flunixin meglumine IM (Banamine, Schering-Plough Animal Health) 10 ml of penicillin G procaine IM (Dura-Pen, Vedco, Inc.), 2 ml of tetanus toxoid IM (Fort Dodge Laboratories), 12 ml of vitamin E/Se IM (Bo-Se, Schering-Plough Animal Health). Reversal was achieved with 50 mg of yohimbine, 50% IV and 50% IM (Yobine, Lloyd Laboratories) The giraffe was able to walk out of the chute within 20 minutes of reversal and was eating and drinking with no signs of pain or discomfort 6 hours later. We continued him on oral Banamine and trimethoprim/sulfadiazine powder (Tucoprim, Pharmacia & Upjohn) for the next 7 days. For follow up, the giraffe was placed in the chute weekly to exam the bands and the scrotum, the scrotum and testes steadily became atrophic and desiccated. In bulls banded by the EZE bloodless castrator the scrotum becomes completely desiccated and drops off within 3 weeks. Three months later our giraffe still had the remnants of his scrotum and testes and although there were no apparent complications, we decided to amputate the scrotum in case the bands would act as a nidus for infection and inflammation. The giraffe was again placed in the chute with bellybands and given 25 mg of xylazine IM, this dose was just enough to perform the amputation without additional anesthesia. The rubber bands were removed with a pair of tin snips and the scrotum was amputated in the crush created by the bands. There was a small area of granulation tissue at the surgical site but no active bleeding. Twenty-five milligrams of yohimbine were given IM for reversal, and the giraffe was bright and alert in 15 minutes. The keepers were instructed to place betadine ointment on the granulation tissue once daily for the next 10 days.

Discussion

We feel we were able to perform this castration in a standing position because of the extensive chute training and conditioning the giraffe received from the keepers. Without having a calm animal in the chute, we would not have been able to castrate him with xylazine alone. The EZE bloodless castrator has been used in the field with cattle for several years, complications noted by the manufacturers are mostly related with poor placement of the bands. If the bands are not placed correctly or tight enough there can be partial vascular and spermatic cord occlusion resulting partial necrosis and the production of toxins leading to endotoxemia and possibly septicemia. We feel the reason that the scrotum did not fall off on its own as it should, was that the tissue on the neck of the scrotum was too thick, if we had performed the procedure on a younger animal the results may have been more or less what was expected. In the future, when planning another castration, we will hope to have the animal chute trained before it is 1 year old, hopefully avoiding having to amputate the scrotum months later.

Acknowledgments

I would like to thank the giraffe keeper staff for their hard work and patience in chute training the giraffe, and the vet staff for all of their assistance.

Literature Cited

1.  EZE Bloodless Castrator. Cowboy Creations, St. Ignatius, Montana, USA.

2.  Bush, Mitchell. 1993. Anesthesia of high-risk animals: giraffe. In: Fowler M, ed. Zoo and Wild Animal Medicine. Current Therapy 3. WB Saunders. Denver, Colorado, 545–547.