A fifteen-year-old, male, castrated American Staffordshire terrier was presented with asubcutaneous, ulcerated mass on the right carpal joint. Thoracic radiographs and abdominalultrasound were both negative for metastatic disease. Punch biopsies revealed the histopathologicaldiagnosis of a malignant peripheral nerve sheath tumor. Due to the extent of the primarymass, local excision was not possible, and amputation of the limb was not an option for theowner. The dog was treated with intravenous administration of combretastatin A4-phosphate,a vascular disrupting agent. A biopsy was taken before and after treatment and power-Dopplerultrasound and contrast-enhanced ultrasound were performed to assess pre- and posttreatmentevaluation of the tumor vasculature. The treatment resulted in massive necrosis of the tumor.