This is all I could find on the subject . I hope it helps.
Considering that these tumors are mostly locally invasive, surgery is the preferred treatment. A margin of up to 3 cm around the tumor has to be obtained, keeping in mind the ability to sew up the wound after surgery. Considering the location and size of the tumor, the surgeon may have to exercise discretion about how best to excise.
Inability to totally excise the tumor may require adjuvant radiation therapy to avoid local recurrence. High grade tumors may not be possible to excise if metastasis has already occurred. In such instances, chemotherapy may be the only option left. Prognosis of spindle cell sarcoma depends largely upon the grade of the tumor and how efficiently local control is obtained,
Protein and Cancer
•Because the amino acids found in proteins can be depleted by cancer cells, some veterinarians recommend a protein diet for dogs with cancer, says Dr. Ogilvie. Fortification of amino acids can decrease canine cancer toxicity. Two noteworthy amino acid types are arginine, an immune-system booster, and glutamine, for gastrointestinal health. Also, glutamine aids in reducing the effects of chemotherapy that can lead to vomiting and diarrhea.
•One of the most critical issues dogs with cancer face is cachexia, or progressive involuntary weight loss. The challenge of keeping weight on a cancer-stricken dog along with the problem of amino acid depletion from the cancer itself, makes a protein diet a smart choice, according to Dr. Ogilvie. http://integrativeveterinaryoncology...20SARCOMAS.pdf