A Protected Contact Approach to Anesthesia and Medical Management of an Asian Elephant (Elephas maximus)
Invasive medical and surgical treatment of elephants managed by protected contact is a difficult and complex undertaking. Protected contact (PC) implies that the animal and handlers remain safe during routine husbandry procedures and access to the animal is restricted. Approximately half of the North American captive elephants are in a PC or voluntary contact program. When intensive medical or surgical procedures are required on PC animals, a successful outcome depends largely on the consistency of cooperation and access.
Foot abscesses are common in captive elephants: in one study5 50% of captive elephants had a foot related medical problem. Gage4 outlined a protracted course of treatment followed by surgery and then postoperative care required by an elephant with phalangeal osteomyelitis. However, the animals that have been treated by these intensive methods are tractable, free contact elephants.1,2 This paper describes the management of pododermatitis comprising of 3 years of medical treatment, including two general anesthetics in a PC elephant.
Ganesha, a 16-year-old, 5,000 kg, male Asian elephant (Elephas maximus) at the Calgary Zoo, developed a fistulous draining tract associated with the left fore second digit. This toe had been treated 5 years previously at another institution before the animal was translocated to Calgary. Purulent discharge was evident from a solar defect with associated onychitis and paronychia above the affected toe. Almost 1.5 years of conservative treatments followed. Access to the affected foot was through a metal mesh welded wall with a “foot door” (8×92 cm, 79 cm from the floor).
Periodic survey radiographs of the left fore were obtained with a Mini X-Ray 300 (MinXray, Inc., Evanston, IL, USA) set at 60 kVp and 1.0 second for A/P views and 80 kVp and 1.0 second for lateral views. A contrast agent (Omnipaque 300, Sanofi Winthrop, Markham, ON, Canada) was used to help define the extent of the tract and monitor bone involvement. The right fore foot was also radiographed as a comparative normal. An attempt at sonography was unsuccessful in further defining the infection.
The toe continued to deteriorate clinically so an intensive flushing regime was started. The tract was irrigated and flushed (SID–TID) with antibiotics based on cultures and sensitivities. Treatment sessions lasted 10–70 minutes and occurred from 1–3 times a day prior to the first surgery. Despite this intensive medical treatment, serial lateral and anterior/posterior radiographs indicated a progression of the osteolytic infection involving the second phalange.
At this point, a decision was made to attempt surgical curettage. Due to the animal’s size, the expected duration of surgery, and our inability to ensure that the elephant was properly positioned during anesthesia, a system of air cushions (Jumbo Lift International Air Cushion Systems) was set up to support the animal. An immobilizing dose of 10 mg carfentanil (Wildnil, Wildlife Pharmaceuticals Canada, Inc., Callander, ON, Canada) was given intramuscularly by restraining the elephant in a hydraulic elephant hugger.
To debride the draining tract, a solar surgical approach was performed. Postsurgical management required the animal to wear a protective boot which was designed by the elephant keepers and constructed at a local tent and awning manufacturer. Once or twice daily bandage changes, as well as periodic radiographs and microbiologic monitoring lasted 14 months before a second surgery was performed.
The second surgical approach was via an incision above the nail to allow an en bloc resection of the distal third of the second phalanx. Intra operative hemorrhage was controlled by elevating the limb with the aid of an overhead hoist. Postoperative infections delayed healing in both cases.
Routine complete blood counts and full biochemical profiles were collected on a regular schedule throughout this period. The elephant presented its ear through an “ear door” (25×92 cm, 135 cm from the floor) in the mesh wall. Ear access also facilitated IV injections for antibiotics or sedatives. Occasionally, usually during musth, sedatives were used to perform very painful or invasive treatments such as removing excess granulation tissue. Standing sedation with intravenous xylazine (Rompun Bayer, Inc., Agriculture Division, Animal Health, Etobicoke, ON, Canada) was required three times to facilitate debridement and flushing of the tract. Careful titration of the xylazine dose (33–72 µg/kg) was required so that it would leave its foot on the foot plate and not become so sedate as to be unresponsive to verbal commands. Partial reversal with atipamezole (Antisedan, Orion Corporation, Orion-Farmos, Espoo, Finland) at 8–14 µg/kg made the animal more responsive in cases of heavy sedation.
The elephant was target trained by bridging and rewarding desirable behaviors and ignoring unwanted behaviors. “Time outs” were effective when the animal stopped responding to commands in a positive manner. The animal learned to approach the open door, turn, and put whichever foot was requested through the foot door opening onto a flat metal stand for treatment. Various types of stands were used to facilitate different approaches to the foot. Although obviously painful, most treatments were accomplished simply by positively reinforcing the desired behavior: leaving its foot out on the treatment stand.
This conditioning process was initiated to ensure the animal’s cooperation in or out of musth, throughout painful and sometimes lengthy treatments. The animal tolerated flushing, debriding, packing, antibiotic infusion, and soaking of this foot. From time to time, the elephant did kick at staff and swipes with its trunk through the foot door did occur.
Radiographs were accomplished by conditioning the animal to place its foot on a piece of plywood the size of our radiograph plates. When the animal could be trusted to place its foot down gently, not crushing the plywood in the process, we attempted both lateral and A/P views. Introduction of the radiograph machine did not require any special conditioning. We had our portable machine mounted on a trolley for easy maneuvering. When radiograph sessions became routine, ultrasound examination was added.
A decision to open the foot surgically to drain and debride the abscess meant we had to ensure we could protect the foot postoperatively from environmental contamination. A sterile bandage covered by a protective boot kept the foot clean and dry. The elephant learned to accept the boot by carefully conditioning the animal to increasing amounts foreign material attached to its foot. Initially, a cloth anklet was rubbed behind its foot, then attached to its ankle until finally the full slip-on boot fastened with three seat belts behind the carpus was accepted. During the conditioning process, the keepers made a point of prodding the foot with an ankus so that the animal would become tolerant of pain associated with this foot. This conditioning was accomplished just prior to the first surgery.
To ensure proper support of as much of the elephant’s dependent side as possible during general anesthesia, preplacement of the air bags was required. This was accomplished after induction and just prior to sternal recumbency. Once laterally recumbent, the bags were inflated, and surgery started. Upon recovery the air bags and support belts had to be removed once the animal had moved off them without leaving them long enough to be destroyed. Ideally, we should have conditioned the elephant to walk into the hugger over the top of these deflated bags to ensure full coverage of the animal’s downside. No attempt was made to accomplish this, although it is probably possible.
Intensive treatment, surgery, and painful postoperative care in elephants is possible in a protected contact management system. Several factors contributed to our success: attention to positive reinforcement of desired behaviors, a slow increase of noxious stimuli, and dedicated keeper staff. Although “surgery is difficult and the aftercare horrendous”3 it is not necessary to omit any treatment modality from an ideal regime. Successful management of PC animals ensures that all captive elephants have access to the same quality of medical care.
1. Boardman, W., R. Jakob-Hoff, S. Huntress, M. Lynch, C. Monaghan, and A. Reiss. 1988. The medical and surgical management of foot abscess in captive Asiatic elephants. In: Proceedings of First North American Conference on Elephant Foot Care and Pathology, Abstracts.
2. Finnegan, M. 1998. Surgical treatment of a foot infection at Metro Washington Park Zoo. In: Proceedings of First North American Conference on Elephant Foot Care and Pathology, Abstracts.
3. Fowler, M.E. 1993. Foot care in elephants. In: Fowler, M.E. (ed.). Zoo and Wild Animal Medicine, 3rd ed. WB Saunders, Philadelphia, Pennsylvania. 448–454.
4. Gage, L.J., M.E. Fowler, J.R. Pascoe, and D. Blasko. 1997. Surgical removal of infected phalanges from an Asian elephant (Elephas maximus). J Zoo Anim Med. 28:208–211.
5. Mikota, S.K., E.L. Sargent, and G.S. Ranglack. 1994. Medical Management of the Elephant. Indira, West Bloomfield, Michigan. 147–148.