Abstract

Chronic right front limb lameness was diagnosed prior to January 2010 in a 19-yr-old neutered male California sea lion (Zalophus californianus). Radiographs of the consistently swollen and warm right carpus revealed variable osteolysis of the osseous structures of the radio-carpal, intercarpal, and carpometacarpal joints with collapse of the joint spaces and instability. Various antibiotics and analgesics provided no resolution. Bilateral cataracts with anterior lens luxation o.d. were also present and prompted surgical attention. Bilateral cataract extraction and an exploratory arthrotomy of the radiocarpal/intercarpal and carpometacarpal joints were performed concurrently. Devitalized bone in each carpal joint was debrided and joints were flushed liberally. A pneumatic tourniquet was secured to the distal radius and an intraosseous catheter placed into the radius distal to the tourniquet. One gram of amikacin (Amiglyde-V^®, Fort Dodge Animal Health, Overland Park, Kansas, USA) was infused to complete a regional limb perfusion over 45min. Collagen sponges soaked with Bone Morphogenic Protein 6 (Infuse BMP-6^®, Medtronic, Minneapolis, Minnesota, USA) were packed into each joint space to promote osteogenesis and to increase joint stability. Histology of bone and synovial membrane revealed widespread severe lymphocytic-plasmacytic inflammation of the synovium and subsynovial connective tissue. Special stains did not reveal bacteria or fungi. All cultures were negative for bacterial growth. The patient recovered well with primary healing of all incisions. Sequential radiographs revealed improved bone density, stability and no further osteolysis. Clinically the patient shows no clinical signs, lameness is resolved, and the sea lion is back on exhibit.

Acknowledgments

The authors thank the staff of Birmingham Zoo, Inc.’s Animal Health Center and Predators Department for their hard work and dedication to this patient.