Sonography currently provides a variety of tools to support the diagnosis and treatment of osteosarcoma and, with the development of therapeutic ultrasound practices, could play an increasingly important role in the treatment of future patients with osteosarcoma. Currently, computed tomography, magnetic resonance imaging, and radiography are the preferred imaging modalities for bone lesions; treatment options for osteosarcoma primarily include highly toxic chemotherapies and surgeries that often result in limb loss. Unfortunately, osteosarcoma is rarely eliminated, and despite this, patients lose their lives after having a significant reduction in quality of life. Evolving therapies such as high-frequency focused ultrasound, ultrasound-enhanced delivery of photodynamic therapy, and low-intensity pulsed ultrasound may offer these patients an improved quality of life while also increasing efficacy of treatment. This canine case study illustrates the various ways in which sonography might contribute to the treatment plan for patients with osteosarcoma. It may provide a comparable model for the reimagining of treatment for future patients with osteosarcoma using a suite of therapeutic ultrasound applications.