SCINTIGRAPHIC DETECTION OF SUBCUTANEOUS METASTASIS IN A DOG WITH APPENDICULAR OSTEOSARCOMA

This report describes the detection of subclinical soft tissue metasta sis of an appendicular osteosarcoma in a dog using bone scintigraphy. A 7-year-old spayed female Rottweiler was presented with a biopsy conf irmed diagnosis of osteosarcoma, Initial radiographs revealed an aggre ssive bone lesion of the left distal radius, At presentation, there wa s no clinical or radiographic evidence of metastasis; however, a nucle ar bone scan showed the primary bone lesion of the distal left radius and numerous soft tissue lesions consistent with diffuse soft tissue m etastases. A left foreleg amputation was performed and cisplatin chemo therapy was given post-operatively. A second bone scan performed one m onth following initial presentation showed progression in size and num ber of soft tissue masses, Many of the lesions had become apparent on physical exam and survey radiographs, Excisional biopsy was performed on one of the soft tissue masses and a diagnosis of metastatic osteosa rcoma was made, The dog was euthanized 2 months after initial presenta tion at the owners request due to deterioration of the animals physica l condition.