<em>By
Alison Mott, Registered Veterinary Technician
Kate Gore, Primary Reptile Keeper
Sacramento Zoological Society, Sacramento, CA</em>

<em></em>

<strong>Abstract </strong>

Management of medical conditions in zoo animals can present unique challenges to veterinary and keeper staffs, often requiring creative solutions.  The Sacramento Zoo was faced with the challenge of how to limit the use of a tortoise’s limb while still allowing the animal to have mobility. While the use of carts for cats and dogs with spinal injuries are common, we took this idea and modified it creating a skateboard for a tortoise. This allowed us to treat and rehabilitate 1.0 sulcata tortoise known as “Bubba.”

<strong>Natural History </strong>

The African spur thighed tortoise (<em>Geochelone sulcata</em>) is native to the northern region of Africa. They range along the southern edge of the Sahara within the countries of Senegal, Mauritania, Mali, Niger, Chad, the Sudan, and Ethiopia.  The sulcata is the third-largest tortoise species, with a weight range of 80-150 lbs. (36-68 kg), and an average carapace length of 24-30 inches (60-75 cm). They are the largest tortoise species from the African continent. The oldest sulcata on record lived to be 54 years-old (Hughes, 1986, in Stearns). Sulcatas are adapted to living in the dry grasslands with thick skin that is resistant to fluid loss in dry conditions; however when exposed to moisture, their skin may become permeable, allowing them to acquire what moisture they need. Like other desert-oriented tortoise species, the sulcata will excavate burrows to thirty inches in depth, and once underground, the burrow can then reach lengths of ten feet or more. As sulcatas are grassland tortoises, they obtain the majority of their nutrition from the grasses on which they graze. In captivity, they will readily eat assorted greens, yams, carrots, with occasional broccoli, squash, and tomatoes as relished treats.

The sulcata species is listed as vulnerable, though they are very common in the pet trade within the United States, despite the Cites Appendix II status. Sulcatas have developed a reputation as a “throw away pet”, due to their large size and destructive tendencies. They can be purchased when they are newly hatched and sized to fit within a child’s hands. Sulcatas grow quickly, are prone to digging large burrows, and as their weights increase, they become more than most people care to handle, and the owners often end up getting rid of the tortoises in any way they can. Zoos and rescue centers are regularly called by people wanting to donate their unwanted tortoises. In October 1999, the Sacramento Zoo acquired the subject of this paper when he was donated by a local veterinarian. As a result of the manner of acquisition, his date of birth and parentage are unknown. Based upon his size, keepers estimated the tortoise’s age to be thirteen years.

<strong>Initial Medical Problem</strong>

Bubba has had an unremarkable medical history with an annual physical exam and radiographs bi-yearly. In 2010 a new tortoise exhibit located between the Giraffe exhibit space and the visitor viewing deck, (approximately 904 sq. ft.), was constructed in combination with the Tall Wonders Giraffe Encounter. The exhibit features a heated house that is approximately 81 sq. ft., while the exhibit yard is a mixture of grass and dirt with small boulders and tall grasses for decorative design. There is a slight slope up to the fence of the Giraffe yard. Bubba shares this exhibit with two smaller sulcata tortoises.

On 25 January 2011 (day 1 of presentation) keepers reported that Bubba had been showing signs of lameness for one day. He was not bearing full weight on his left front leg. Keepers were advised to monitor and report back to veterinary staff if the lameness persisted or worsened.  On 31 January 2011 (day 1 of treatment) the lameness had increased to non-weight-bearing and a full physical exam was performed. During his exam, radiographs of the left front limb were taken and showed irregularities in the margins of the elbow and carpal joints consistent with osteoarthritis. The left distal humerus had areas of focal radiolucency, and a possible bone fragment. He was given an injection of Meloxicam, a non-steroidal anti-inflammatory (NSAID), for pain. Bubba was returned to his exhibit and keepers continued to monitor his lameness.

<strong>Medical Treatment</strong>

On 1 February 2011, Bubba was placed on oral Meloxicam every other day and Tramadol once daily. Tramadol is a synthetic opioid analgesic used to treat moderate to severe pain. While it was hoped that a combination of analgesics would help alleviate Bubba’s pain, it was obvious two days later that his condition was not improving. He was moved to the Dr. Murray E. Fowler Veterinary Hospital. The hospital has a room dedicated specifically for sick birds or reptiles that can be modified to fit the specific needs of the animal hospitalized. In Bubba’s case, he had free access to the entire room with a 250-watt radiant heater hung from the ceiling three feet off of the floor to give him a basking spot while the room temperature was set to maintain a range of 75 to 85 degrees Fahrenheit. Due to the concerns that there may be osteomyelitis in the leg and further use of the leg might worsen the condition, the staff wanted to keep Bubba from using or bearing weight on the front left leg. For most mammals this would be a bandage that brought the leg up to the body or a splint which restricted movement. These animals are able to ambulate without problem on three legs. Tortoises, however, require the use of all limbs to raise themselves and move. Turtles and tortoises must rely exclusively on movements of the limbs to propel themselves.  The challenge was how to keep a 41kg tortoise off of a limb. The veterinary staff needed a device that would keep Bubba’s weight off of his leg, but still allow him to move freely. The Maintenance Department was consulted and tasked with constructing a tortoise cart the following day while the veterinary staff performed a follow-up examination.

Due to the lack of improvement in the tortoise’s condition, additional diagnostics were performed on 4 February 2011. This exam included a blood culture, arthrocentesis [or joint-tap (fig 2)], Complete Blood Cell count (CBC), blood chemistry panel, additional radiographs and obtaining an accurate body weight (41kg). Radiographs of the left front limb showed marked irregularity at the joint margins with areas of bony proliferations and lysis at the distal humeral condyl. These results were more consistent with osteomyelitis or neoplasia rather than trauma. The arthrocentesis results showed mild mononuclear inflammation most compatible with a degenerative joint disease. While under anesthesia, the maintenance department took measurements of Bubba and outlined the plastron using a towel and a black marker. The cart was constructed out of 1” plywood, four wheels and two nylon straps.  The wood was cut to include a place for the left front leg to rest and all edges were rounded and smoothed.  While Bubba recovered from anesthesia he was strapped onto the cart. After a few days of walking around on his new cart it was obvious that a few modifications were needed. Bubba was having a hard time reaching the ground with his back feet, the straps kept breaking, he was still able to use his front left leg and he was becoming very good at doing wheelies with his front right foot. The cart was taken back to our maintenance department where the rear wheels were sunk into the wood (to lower the back of the cart), a fifth wheel was added in the middle rear area, rubber padding was installed on the cart to prevent sliding, the straps were replaced with heavier nylon versions and a leg guard was placed on the front of the cart to keep the left leg from being able to bear weight (fig 3).<img class="alignright size-full wp-image-2504" title="bubba-on-cart" src="http://aecetia.net/gws/aazk/wp-content/uploads/bubba-on-cart.jpg" alt="bubba-on-cart" width="714" height="511" />

On 10 February 2011, Dr. Allison Zwingenberger, a Radiologist at the University of California at Davis Veterinary Medical Teaching Hospital (UCD VMTH), was consulted and agreed that the radiographic bone changes were likely the result of an infection. Bubba was started on Ceftazidime injections (three times a week), a broad spectrum cephalosporin antibiotic. Bubba’s activity and appetite had decreased since he was placed on the cart and he had started to refuse all oral medications; as a result his oral Meloxicam treatment was changed to a daily injection. As he spent the majority of his time under the basking heater, veterinarians and the curator were asked about the possibility of giving Bubba some time outside on warm days. Permission was granted and he was allowed time outside behind the Veterinary hospital on days that were above 70 degrees Fahrenheit and sunny. On 13 February 2011 he spent his first 4 ½ hours outside with some supervised time spent grazing. This was the most active he had been in some time. He had figured out that the asphalt behind the hospital sloped slightly and he would walk up one end and slide down. This was only about five feet long, but he appeared to enjoy it. He also became very adept at climbing hills with his cart. The grassy area behind the hospital is a slight hill; using his three available legs he would climb the hill to get to his favorite patches of grass. He was allowed unsupervised time outside when he was confined to the asphalt, but had to be supervised when grazing in case he got stuck in mud or flipped over while climbing. (fig 4)

Bubba’s appetite remained decreased, until it was discovered that by flipping his food dish over and offering his diet on top, (a difference in about two inches of height), Bubba was better able to reach his food and ate readily.  Leaving his food this way was not practical as Bubba would knock the food off of the bowl and have difficulty eating it off the ground. Reptile keeper Bill Tabb was asked to make a raised food bowl. Using two plant saucers that were placed bottom to bottom and attached together with three screws, he devised a raised feeder. Bubba made his own modifications to the food bowl over the next week by pinning the food bowl against the wall with his cart. This cracked the top bowl and made an indentation in one side. The cracked piece was removed and edges of the food bowl were smoothed. This was the best spot for Bubba to eat his food (fig 5).

After three weeks of treatment, the leg guard was removed during the day. Veterinary staff wanted to assess the use of the limb without letting Bubba place full weight on it. He was observed letting the leg rest on the cart multiple times throughout the day. While his leg appeared visibly swollen at the elbow joint, the swelling had decreased from the initial presentation. The leg guard was placed back on the cart the following morning and Bubba continued to improve on his cart.

Veterinary staff performed a follow-up examination 37 days into the treatment. The examination included repeat radiographs, arthrocentesis, CBC and blood chemistry panels. Over the previous five weeks of hospitalization his weight had remained steady and appetite returned to normal.  He was anesthetized for the examination. Contracture of the muscles around the left elbow was appreciated. There was resistance to the manipulation of the joint and no appreciable crepitus,…….

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