Radiographic Evaluation of Carpal and Tarsal Joints Associated with Osteoarthritis in a Group of Seven African Elephants (Loxodonta africana): Suggestions for a Change in Strategy When Evaluating Elephant Health
Abstract
The AZA standards for elephant management require institutions holding elephants to obtain baseline sets of radiographs of the feet for evaluating potential infections, fractures or metabolic conditions.1,4
In January 2012 a 51-yr-old female African elephant (Loxodonta africana) was euthanized due to severe progressive degenerative osteoarthritis. The elephant was maintained on chondroprotectants and analgesics. The carpal and tarsal joints from all four limbs were radiographed then imaged with Computed tomography (CT). OsiriX® software was utilized to develop three-dimensional images of the carpal and tarsal joints. Gross evaluation was then compared to radiographic and CT images. In all images, severe degenerative joint disease (DJD), including ankylosis, joint space collapse, enthesiophytes, and osteophytes were observed. Extensive subchondral bone exposure was observed in most articulating surfaces.
Radiographic techniques were developed to image the carpal and tarsal joints in a group of six female African elephants ranging in age from 28- to 45-yr-old. All elephants demonstrated varying degrees of DJD without significant changes to the digits. Some lesions were comparable to findings observed in the aged female. Only three of the six elephants demonstrated clinical signs comparable with osteoarthritis and all elephants were placed on chondroprotectants; three individuals were placed on analgesics at previously documented pharmacokinetically studied doses.2 Banked sera was evaluated for Mycoplasma sp. titers which have been associated with DJD in elephants;3 all were negative.
It is strongly suggested to consider inclusion of carpal and tarsal radiographs when evaluating the appendicular health of elephants. Further evaluation of appendicular health in these elephants is ongoing.
Literature Cited
1. AZA Standards for Elephant Management and Care. 2011.
2. Bechert, U., and J.M. Christensen. 2007. Pharmacokinetics of orally administered ibuprofen in African and Asian elephants (Loxodonta africana and Elephas maximus). J. Zoo Wildl Med 38:258–268.
3. Schmitt, D.L. 2003. Proboscidea (Elephants). In: Fowler, M.E. and R.E. Miller (eds.). Zoo and Wild Animal Medicine. Elsevier/Saunders, St. Louis, Missouri. vol 5:547–548.
4. Siegal-Willot, J., A. Alexander, and R. Isaza. 2012. Digital radiography of the elephant foot. In: Fowler, M.E. and R.E. Miller (eds.). Zoo and Wild Animal Medicine. Elsevier/Saunders, St. Louis, Missouri. vol 7:515–523.