Scintigraphic and radiographic evaluation of appendicular skeletal lesions in cold-stunned Kemp's ridley sea turtles

Osteolytic appendicular skeletal lesions in eight-stranded, cold-stunned Kemp's ridley sea turtles (Lepidochelys kempii) were evaluated using radiography and skeletal scintigraphy. Radiographic studies were performed monthly in most animals. Follow-up scintigraphy was performed 45-120 days after the initial exams in six turtles. Radiographically, lesions slowly progressed from an early osteolytic process contained to either the proximal or distal end of long bones, to a later stage characterized by thickening of the affected bone, sclerosis, and remodeling of the lesion borders. In seven turtles, the initial scintigrams were characterized by at least one focus of abnormal radiopharmaceutical uptake that correlated with a lytic site noted in radiographs. In five turtles, scintigraphic lesions were characterized by asymmetric radiopharmaceutical uptake rather than by increased intensity of uptake. Scintigraphic studies obtained more than 4 months after the appearance of clinical and radiographic signs had minimal, if any, abnormal radiopharmaceutical uptake, despite the persistence of abnormal radiographic findings. Skeletal scintigraphy is an effective method for more precisely determining if and when these animals can be returned to the wild. Animals were released if normal radiopharmaceutical uptake was seen during initial examination, or if decreased uptake was noted between serial examinations. In four of the turtles, resolution of abnormal scintigraphic findings permitted an objective decision to discontinue antibiotic and antifungal therapy. Seven of the eight turtles were released after correlation of the clinical signs with the imaging findings. Radiographs, however, are still needed to facilitate the correct identification of lesions with scintigraphy.