<p>The mammary gland, except for the skin, is the most common site for presentation of neoplasms in females; It is between 25 and 50 % of the overall presentation of these cases and 82 % of the reproductive tract. It is the most common malignant tumor and of these, about 50 % are benign and 50% are malignant. This is more common in females (97-100 %) than in males (0-3 %) and no hysterectomized elder females are more susceptible with increased caudal glands presentation, because it has more number of cells sensitive to tumor transformation.<br>Early hysterectomy has a protective effect for the development of tumorigenesis; if performed after two and a half years of life this protective effect is almost null. The diagnostic method of choice is the histopathological study, as many people (owner, students and veterinarians) at observing the breast mass, immediately diagnose as a breast tumor, without previous studies (especially pathological). The treatment of choice is surgical resection, except for inflammatory carcinomas, this procedure is curative in 50 % of patients with malignant breast tumors. Finally, the prognosis depends on the tumor stage as classified by the World Health Organization (WHO). The aim of this is to perform a literature review concerning etiology, clinical examination, diagnosis, classification and treatment traditionally used in the mammary gland neoplasms.</p>