Soft tissue sarcomas that occur in cats under the skin of the neck, between the shoulder blades, the flank, and in the back leg muscles are often termed injection site sarcomas, or vaccine associated sarcomas, due to their anatomic location at common sites for subcutaneous injection, particularly rabies and feline leukemia vaccines. Metastasis at the time of diagnosis is uncommon; however, thoracic radiographs should be obtained as the most common site of systemic metastasis. Dogs with grade 1 and 2 tumors have a high likelihood of recurrence after conservative surgery, but approximately 90% are tumor free 12 months after aggressive surgery. A combination of both surgery and high doses of radiation therapy provides the best chance of controlling otherwise inoperable tumors. Postoperative pain relief is the most important aspect of treatment for dogs with soft tissue sarcoma.