Treatment of Canine Mammary Tumors

A large variance exists in the appearance and behavior of canine mammary tumors.  Each tumor needs to be evaluated individually.  More than 50 % of canine mammary tumors are cancerous with the other 50% diagnosed as benign or non-life-threatening. 

A malignant tumor is cancerous and often has an irregular shape.  A treatment plan must be determined by the veterinarian in agreement with the pet owner.  The age and health of the dog must be taken into consideration as well.  Depending upon the specific size, type, and area encompassed by the tumor; surgical removal may be a recommended option.  Chemotherapy and/or radiation therapy may be administered as a follow-up procedure to destroy any remaining cancerous cells.  Depending upon the severity of the disease, chemotherapy usually lasts for a period of six months.

Prior to removing a mammary tumor, the veterinarian will perform a needle biopsy or removal of cells from the tumor.  This is less expensive and less time-consuming than removing the whole tumor for biopsy.  Radiographs can be used to look for tumors in the internal organs.   CT scans can also be used to determine if the tumor has spread to the dog's internal organs.  A smear of cells from the tumor can be observed under a microscope to make a determination as to whether the tumor is malignant or benign.

Malignant tumors should be removed right away, benign tumors may not need to be removed, just observed for any changes in size or behavior.  Small, benign tumors may not have any effect upon the dog’s reproductive capacity.

Pet owners noticing any lumps near their dog's mammary glands should bring the growth to the attention of their veterinarian.  Chances for the dog’s survival are much greater with an early diagnosis and initiation of a treatment plan.  Many tumors can be successfully treated