Case Description—A 5-year-old sexually intact male Giant Schnauzer was evaluated because of difficulty breathing and left pelvic limb swelling. Eighteen months previously, the patient had had intermittent left pelvic limb swelling, but the owner declined further testing at that time.
Clinical Findings—Physical examination revealed severe pitting edema of the left pelvic limb and prepuce and muffled heart sounds on thoracic auscultation. Results of thoracic radiography and thoracocentesis were consistent with chylothorax, and CT imaging of the thorax and abdomen revealed a mass involving the whole left sublumbar area.
Treatment and Outcome—In an attempt to treat the chylothorax, pleural omentalization and pericardectomy were performed. Histologic evaluation of several biopsy specimens harvested in the abdominal and thoracic cavities revealed disseminated lymphangiosarcoma. The patient recovered well from surgery, and mitoxantrone chemotherapy was administered. As of 10 months after surgery, the dog was clinically normal except for mild pelvic limb edema.
Clinical Relevance—The combination of clinical signs, multiple imaging features, surgical findings, and histologic examination findings enabled the final diagnosis of lymphangiosarcoma. Clinical management that included medical and surgical treatments and chemotherapy resulted in improved quality of life and extended survival time in a dog with metastatic lymphangiosarcoma.