Case report: appendicular osteosarcoma concurrent with bladder distension in a dog

Abstract

Osteosarcoma (OSA) is the most common primary bone neoplasm in dogs, characterized by aggressive behavior, rapid growth, local bone destruction, and high metastatic potential, mainly to the lungs. This study reports a clinical case of vertebral osteosarcoma concomitant with neurogenic bladder (bexigoma) in a female German Shepherd dog, presented with pelvic limb paraparesis, cachexia, prostration, and abdominal distension. Physical examination revealed absence of neurological reflexes, severe bradycardia, and a distended urinary bladder upon palpation. Laboratory findings showed normocytic anemia with apparent hyperchromia, marked neutrophilic leukocytosis with left shift, and lymphopenia, suggestive of severe systemic inflammation. Radiographic evaluation demonstrated osteolytic and proliferative lesions in multiple thoracic and lumbar vertebrae, highly indicative of bone neoplasia with possible metastatic spread. The main diagnostic hypothesis was vertebral osteosarcoma with spinal cord compression, with osteomyelitis considered less likely. Due to the severity of the condition, the poor prognosis, and the owners’ financial limitations, humane euthanasia was elected. Postmortem histopathological analysis confirmed the diagnosis of osteosarcoma. The presence of a distended bladder, likely secondary to neurogenic dysfunction, added complexity to the clinical management. This case highlights the diagnostic and therapeutic challenges posed by axial skeletal tumors, emphasizing the need for an integrated clinical approach, thorough imaging, and the consideration of socioeconomic factors in clinical decision-making. Furthermore, it underscores the importance of case reports as valuable educational and scientific tools, especially when dealing with atypical presentations or comorbid conditions.