Incidence rate of breast cancer, clinical and ultrasound approaches to diagnosing the same in dogs

Mammary gland tumors in dogs rank second among all newly diagnosed tumors in this species. Research goal was to studyclinical/morphological characteristics of breast cancer in dogs with the use of ultrasound investigation. 34 dogs of differentbreeds and age groups with spontaneously emerging neoplasms of mammary glands were chosen for the study. To classifymalignant tumors, the histological classification was applied. Complete examination of breast tumors was carried out with thehelp of clinical observation, ultrasound, radiologic, hematological and ultrasonographic methods applied. The largestpercentage (23.5%) of animals with mammary gland neoplasms are mongrel female dogs. The breed predisposition wasdetected in dogs of the following breeds: Miniature Schnauzer - 11.9%, Standard Dachshund - 11.9%, American Bulldog,American Cocker Spaniel and Miniature Poodle - 8% each. Breast cancer was diagnosed in 29 animals (85.3%), 100% of thosecases in the nodular form with microcalcifications in the tumor parenchyma. The horizontal orientation of growth is more oftentypical of breast cancer in the mammary gland pairs I and II at the initial stage of carcinogenesis, and is characterized by aninhomogeneous hypoechoic structure with sufficiently pronounced boundaries detected during the ultrasound investigation.The vertical orientation of growth is mainly typical of breast cancer in the mammary gland pairs III, IV and V from the verybeginning of the disease. The ultrasonography usually shows: inhomogeneous hypoechoic structure containing inclusions inthe form of cords or foci of a higher acoustic solidity; also clearly defined lateral acoustic shadows and dorsal echoenhancement; as well as unevenness and indistinctness of borders. The performed histological study within the currentresearch revealed a multifocal, infiltrating epithelial neoplasm with distinct edges, surrounded by a large amount of fibroustissue. The tumor consisted of a number of acini with a tendency of forming a network structure. The shape of cells wasdetected from round to irregular, the cytoplasm was found scarce, often with uneven borders, with the large central core, withchromophilic substance and 1-2 nucleoli. The cells were characterized by the pronounced anisocytosis and anisocariosis, and agreat number of mitotic figures. Lymphatic invasion was observed. Ultrasound investigation of the mammary gland allows forperforming percutaneous minimally invasive interventions and differential diagnostics of cystic and solid lesions of themammary gland (96-100% accuracy), mastopathy and carcinoma conditions.