CLINICAL STUDIES ON CANINE MAMMARY TUMORS

A clinical study was conducted on 72 dogs presented for the treatment of canine mammary tumors. Highest incidence of CMTs was observed in the age group of 10-12 years. Spitz was the most commonly affected dog breed. Majority of the tumors were less than 3 cm in size, followed by 3-5 cm in size.Inguinal glands were the most commonly (44.44%) affected glands. Most of the tumors were non pedunculated and were fixed to the skin. Thoracic radiography revealed distant metastases in lungs. Malignant CMTs had higher AgNoR counts. Different treatment modalities like surgical excision, chemotherapy with doxorubicin and cyclophosphamide, combination of surgery and chemotherapy and surgery and hormonal therapy with tamoxifen were studied. Most of the CMTs were malignant. Adenocarcinomas were the most common type. Immunohistochemical studies revealed hormonal dependency in mammary carcinogenesis of majority of CMTs. PR expression was evident in most of the adenocarcinomas. P53 immunoreactivity was evident in 27.2% of malignant CMTs and C-erb oncogene expression in 33.3% of tumors that were positive for either ER or PR.