Abstract:Ductal papillary carcinoma of the canine mammary gland is a kind of canine mammary gland tumor, which is a malignant tumor. It mostly occurs in middleaged and elderly unsterilized female dogs. Clinical symptoms are lumps in the breast, varying in size, growing rapidly, and tumors can develop in one or more glands. In the case of advanced metastases, the cancer has spread to the lymph nodes, lungs, colon, kidneys, and sometimes bones, and the prognosis is usually good if surgery is performed early. This article introduces the clinical diagnosis and surgical treatment of an 8yearold female dog with intraductal papillary carcinoma of the mammary gland in detail, in order to provide a reference for the clinical diagnosis and treatment of canine mammary gland tumors.