"THIS LITTLE PIGGY HAD A HOOF TRIM"

Training a Warthog for Hoof Work

By Pilar Hicks, Keeper

Disney s Animal Kingdom

Lake Buena Vista, FL

Introduction

Several species of hoof stock experience problems with a variety 0( hoof conditions due to many factors including genetics, inadequate substrate, and nutritional deficiencies. When chronic conditions occur, typical treatment is physical restraint or chemical immobilization of the animal to examine and treat the affected hoof. Often times, this may lead to multiple immobilizations to treat the hoof properly. At Disney's Animal Kingdom (DAK), one of the adult female warthogs (Phacocoerus africanus) had an outer wall separation of the front left, lateral hoof. Kicha's condition was deemed chronic and one that would need much attention and care throughout her life. Because of the ease with which she could be trained, she was deemed a good candidate for attempting hands-on hoof examination and trimming, through operant conditioning. Our goal was for the training program to eliminate or at least substantially reduce the need for numerous chemical immobilizations and thus to prevent excessive stress on the animal. With patience and teamwork, we were successful in training a series of behaviors that allowed us to work on her feet in a protected contact environment. We currently work on her front hooves once a week. This paper will focus on how this training process was achieved by defining, testing, changing and discarding a variety of techniques in order for the hoof presentation and trimming behaviors to work for Kicha in a positive, non-invasive manner.

General History

DAK houses 1.2 warthogs; however, Kicha is the only warthog that has experienced hoof cracking and separation. Kicha was born in May of 1996. Before coming to DAK, Kicha broke her left, front leg when she was five months old. The leg was pinned and it healed well. However, we believe this injury may have contributed to the hoof separation as her hoof wears abdominally when she walks (presumably due to the early stages of arthritis). Our plans to condition the warthogs to hoof work were essential to monitor her condition.

When Kicha was chemically immobilized for her annual exam in March of 1999, we observed significant damage to her left front hoof. On daily checks we had seen some chipping and cracking, but once the decaying parts of the hoof were removed it was evident that she was experiencing hoof separation. This caused a pocket where debris (mostly dirt and feces) was impacting the hoof causing further infection and sloughing. The animal care team decided to take an aggressive approach in getting our hands on her hooves on a regular basis. And so began the quest to trim Kicha's hooves.

The Training Area and Equipment

We began training Kicha in a transfer chute area that contains a floor scale. The transfer chute connected the bedroom stalls with the outside paddocks. The sides of the transfer chute were equipped with vertical removable bars that allowed the keeper to access the animal (see Figure I). It is important to remember the safety of the animals and the trainers at all stages of training when designing an access area. As training progressed these bars were lengthened to allow more maneuverability for the trainer.

A typical training session lasted from five to 15 minutes depending on the behaviors the keeper was working that day and the response of the animal. One apple and three to four pieces of monkey chow were used as rewards per daily session. The monkey chow was used as magnitude reinforcement for a great response or at the end of a long behavior (e.g. dremmel trimming or rasp work). There was also a wooden box positioned within the chute that reduced the width of the chute and allowed the animal to remain within reach of the keeper.

Figure I. The training area with removable bars.

Training the behaviors

At DAK under the guidance of the Behavioral Husbandry Team, all teams are required to submit a training plan to their managers for approval. The training plan is a general outline of the steps the trainer will follow to accomplish the ultimate goal, including contingency plans based on the positive or negative responses of the animal. Kicha's easygoing attitude was the foundation of my plan, as in addition to food rewards, Kicha was already very receptive to tactile reward. She routinely laid down and over on her side while being brushed and rubbed (see Figure 2). While still in protected contact per our training plan, we began manipulating her front and back feet while she lay in this position. Her front feet were much more sensitive than the rear feet. She allowed her primary trainer to rub them; however, it was for short periods of time, often pulling her foot away to avoid the touch. We worked to increase the length of time she remained still while manipulating her feet. While this was great progress in the training, Kicha remained leery of people present other than her primary trainer while she was in this position.

The introduction of a second person became vital to our training plan, and Zoological Manager, Steve Castillo, was chosen. His role was to trim and work on her hooves on a regular basis and to become the second trainer. Twice a week, he initially came down to watch and then to integrate into the training program. As Kicha saw him more frequently, she relaxed and accepted him manipulating her feet. Eventually, Steve was able to apply a Hoofshield conditioner to her front hooves in the down position once a week. (Hoofshield is a conditioning liquid that aids in strengthening the hoof wall.) We hoped this conditioner would decrease the amount of chipping. Steve was also able to minimally trim the front hooves while the warthog was in this position. Kicha was very calm and remained steady during this phase of the process. However, as more invasive filing and trimming began, Kicha did not stay in her down position. She continually retrieved her leg or got up and left the area. It was decided that this position was no longer safe for the animal or the trainers given our long-term goals.

In the new position, Kicha was trained to sit directly facing the trainer. This was found to be an easier way to apply the Hoofshield conditioner on her front hooves. While the primary trainer fed her, keeping her head up, another person (usually Steve) applied the Hoofshield and examined the hoof noting any new chips or sloughing. Kicha was notably more comfortable in this position, presumably because she could see all people present. One day, I pulled Kicha's left front foot up onto the ledge of the door to get better access and visibility of the hoof. Kicha responded well to this new position and we added this component to our training plan. This worked well as the trainer could gently hold the leg on the inside of the training bars without interfering with the examiner's grasp of the hoof on the outside of the training bars. This behavior was called "Foot Up" as illustrated in Figure 3.

Figure 2. Kicha being brushed in the down position.

Figure 3. Foot up position rinsing the hoof

A variety of rasps were introduced to Kicha and seemed to have very little effect on her. It appeared that as long as she was getting rewarded for staying in position, she was comfortable with keeping her foot up. These rasps were the key to getting a handle on the sloughing of the outer wall. A wood block was cut to fit between the training bars to elevate Kicha's foot. This enabled Steve to file the hooves with the rasp without the ledge of the door interfering in the work.

While the sloughing of the hoof slowed, we occasionally saw small chips that quickly deteriorated the hoof wall. It was decided to attempt to introduce a dremmel tool to file the rough edges that could be catching or snagging while she walked. Kicha did not react to hearing the dremmel for the first few times and she seemed comfortable when Steve filed her foot for the first time with it (see Figure 4).

Once the hoof area was cleaned and filed, there were still small divots that sometimes filled with debris. We applied acrylic to these areas to prevent impaction or infection. The amount of time that the acrylic remained on her foot varied [four days was average]. We noticed that the drying time for the acrylic was dependent on humidity levels and temperatures of the day. We introduced Kicha to a hairdryer (again, with no reaction from Kicha) to quicken the drying time of the acrylic allowing the chemicals to bond more strongly (see Figure 5), and saw an increase in the amount of time the acrylic remained on with this process. Yes, we were running one heck of a beauty salon but we did stop short of painting her nails!

Figure 4. Using the dremmel

Kicha's diet was supplemented with Biotin to help initiate wall growth.  The direct effect on the hoof growth
was hard to determine as we began hands on work with her feet simultaneously. She was also put on Cosequin to treat the effects of the arthritis. We believe the combination of the diet supplement, joint promoter, and the hoof work has allowed the hoof to grow out and wear normally. To date, Kicha's left front hoof has grown out nicely and maintenance work is done once a week.

Figure 5. Using the hairdryer to set the acrylic.

We now have expanded the hoof work to include rear hooves and dewclaws. As stated at the beginning of the paper, her front feet were the most sensitive in the down-over position. In contrast, the rear feet were not particularly sensitive (see Figures 6a-c). With Kicha lying on her side, I rubbed her chest and stomach, while Steve used a rasp, dremmel or snippers to work on the hind feet. No food reward was given during the trimming; the reward was completely tactile. When Steve was finished with the hoof work, she was given pieces of apple and monkey chow. Currently, she remains in position for about two minutes and we are working on extending that time.

We now know what works and what doesn't work for hoof work as it relates to our access area and the tolerance levels of the animal. People often ask "How long did this take to accomplish?"

Overall, the time frame was approximately six months but the majority of that time was spent looking for the best positioning and access to the feet. Kicha was easygoing and accepting of most things immediately. It was often my apprehension of progressing too fast that slowed some progress such as the introduction of the dremmel and the hairdryer. She has been an extraordinary animal.

Figure 6a. Kicha in the down position.

Figure 6b. Checking the rear hooves for any damage

Figure 6c. Using the snippers to trim rear dewclaws

The primary thing I have learned from this training project is that you never know what you can achieve unless you try. The original goal of this project was to file the hoof weekly with a rasp in order to prevent further sloughing. With the cooperation of the warthog training team and Kicha, we were able to take this goal to many levels. To see other examples of husbandry training at Disney's Animal Kingdom as well as information about planning and documenting training sessions, see www.animaltraining.org

Acknowledgements