MAMMARY-TUMORS IN THE DOG - FREQUENCY AND COURSE

In the presented retrospective study incidence, age and breed distribu tion of canine mammary gland tumors in the patient population of the S mall Animal Clinic, School of Veterinary Medicine, Hannover, are exami ned. In addition, survival rates and the frequency of tumor recurrence and/or distant metastasis following surgical resection are shown. Com prising 41.6 per cent of all neoplasms in the female dog, mammary glan d tumors have to be considered very important especially in the older, intact bitch. Of those mammary gland tumors that underwent histopatho logical examination up to 75.6 percent were read out as being malignan t, the adenocarcinoma and carcinosarcoma representing over half of tho se cases. In 49.3 per cent of the cases that were followed up tumor re currence and/or metastasis (mainly pulmonary) had occurred within one year after surgery. 37 per cent of the dogs we were able to follow up on died within the first year after tumor removal, in 90 per cent of t hese cases the cause of death was reported to be directly related to t he tumor. The adenocarcinoma of the mammary gland exhibited the most g uarded prognosis. The presented and earlier studies demonstrate unsati sfactory results in canine mammary gland tumor recurrence and rate of metastasis which implies the necessity for additional therapeutic appr oaches in this important canine neoplastic disease. This aspect is und erlined by the fact that questioned owners exhibited very postive opin ions towards post-operative chemotherapy in cases of malignancy. This not only demonstrates a willingness to seriously consider such a treat ment but also reflects a certain request for recent treatment modaliti es for their animals. Further studies on peri- and post-operative ther apy of canine malignant mammary gland tumors are mandatory.