Sixteen dogs with a variety of malignant tumors were treated with low-dose cisplatin(CDDP) as adjuvant chemotherapy after surgery. The dogs were given cisplatin intravenously(I.V.) at a dosage of 20-30mg/m²of body surface area at 2-or3-week intervals. CDDP was administered in the following manner: Saline(0.9% NaC1) at 10-20ml/kg/h was administered for 1 hour. CDDP diluted with saline was then administered I.V. over 1 hour after administration of metoclopramide hydrochloride S.C. and butorphanol tartrate I.V. or S.C. After CDDP administration, another saline infusion(10-20ml/kg/hour) was continued for 30 minutes or 1 hour. The dogs received a total of 110 doses of cisplatin, with an average dose of 24.2mg/m²and the median number of doses of six(range, 3-15 times), and the median cumulative dose was 145mg/m²(range, 60-320mg/m²). Adverse events were seen in 10 of 16 cases, including six vomiting, two anorexia, and two neutropenia. According to the Veterinary Co-operative Oncology Group classification of chemotherapy side effects from grades I to V, these cases were mild(grade I to II), and none of the dogs required hospitalization. These results suggest that low-dose CDDP therapy was a safe method of adjuvant chemotherapy after malignant tumor resection, though further study with a larger number of cases is needed.

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Objectives: To assess the efficacy of local treatment for canine well-differentiated maxillary and mandibular fibrosarcomas.
Methods: A retrospective analysis of 31 case records was conducted to evaluate the differences in tumor-free survival time and overall survival time between treatment and no-treatment groups.
Results: The overall mean tumor size and median survival time for 29 dogs was 6.5 cm and 270 days, respectively. There was no significant difference between the tumor sites(p=0.420). A significant difference(p=0.008)was found in the median survival time between the local treatment group(592 days)and no-treatment groups(162days). In the subgroup analysis, a significant difference(p=0.027)was found in the median tumor-free survival time between the cases without radiation therapy(68 days)and those with radiation therapy(515 days). Local tumor progression(n=16)was one of the most common causes of death; yet, death was delayed with a combination of surgery and post hypofractionated radiotherapy.
Clinical Significance: The significantly shorter survival time of the no-treatment group confirmed the poor prognosis of canine well-differentiated maxillary and mandibular fibrosarcomas, when it is not treated. Carefully planned local treatment such as a combination of surgical excision and radiotherapy can ultimately extend survival time for this tumor.

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Two dogs with gingival lesions were treated with simultaneous tooth extraction and lesion removal. The lesions were diagnosed as squamous cell carcinoma, and due to early recurrence, the dogs were brought to the Azabu University Veterinary Teaching Hospital. Computer tomography(CT)findings confirmed nasal cavity invasion in both cases. In Case 1, radiotherapy was performed, and in Case 2, resection, intraoperative radiotherapy, and postoperative radiotherapy were performed. Subsequently, both cases received carboplatin and piroxicam treatment. No sign of recurrence has been seen for two years in Case 1 and one year in Case 2. Because tooth extraction can facilitate the spread of gingival lesions to the nasal cavity, it is important to perform a histological analysis prior to tooth extraction.

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