A 9-year-old male okapi (Okapia johnstoni) was examined by Tampa’s Lowry Park Zoo veterinary staff on 13 November 2012 for acute onset right thoracic non-weight bearing limb lameness. The animal reportedly injured himself on the fencing from the enclosure. The initial examination revealed crepitus and laxity of the right carpus when flexed mediolaterally. Radiographs revealed soft tissue swelling overlying the first row of carpal bones. Ultrasound exam showed tears in the latero-distal suspensory ligament. The animal was managed conservatively with bandaging, nonsteroidal anti-inflammatories, and stall rest. On 11 February 2013, radiographs revealed mineralization of the abaxial and collateral ligaments between P2 and P3 of the lateral digit, periosteal exostosis and extensive mineralization of the torn suspensory ligament. Surgery performed on 21 February 2013 removed osteophytes and bony exostosis associated with the proximal interphalangeal joint, suspensory ligament and damage to the retinaculum. The animal remained clinically lame, and recheck radiographs on 19 July 2013 revealed recurrence of severe boney exostosis bridging the proximal interphalangeal joint. Due to concerns for quality of life, surgery for digital amputation with disarticulation at the proximal interphalangeal joint was performed on 2 August 2013. This technique was preferred over amputation at the distal mid-phalanx due to surgical access and suspected ease of postoperative management. Six months postoperatively, the okapi remained mildly lame, but was overall clinically improved. Limb salvage procedure can be adapted from domestic livestock to endangered species to provide higher welfare standards while maintaining opportunities for breeding.
The authors graciously acknowledge Tampa’s Lowry Park Zoo’s section curator and husbandry staff.