Mammary gland tumors, also known as breast cancer, can occur in female dogs between the ages of 5 and 10, according to veterinarian Race Foster of PetEducation.com. This condition is most frequently seen in female dogs who have not been spayed or were spayed later in life. This condition does not frequently strike male dogs or females that were spayed early in life. This is the easiest form of cancer to prevent in dogs, Foster says.
-
Symptoms
-
Often, dogs who develop mammary gland tumors do not show many symptoms in the early stages of the condition, according to veterinarian Jeffrey Philibert of the University of Minnesota. Typically mammary gland cancer is not discovered until it is in its late stages and is usually noticed while palpating the breasts of the dog. There may be some decrease in appetite and energy levels, and there may be some swelling in the dog's nipples, but these are not common. Ulcers that cause secretion of pus from the nipples is not noticeable until very late in the condition.
Diagnosing
-
If the veterinarian notices a small solid mass in the dog's mammary glands during a physical exam, he may request tests. This mass will feel as though it is attached to the skin and will not shift during palpation. The requested tests will include a full blood work, urine analysis and X-rays. These tests will help to determine the likelihood of cancer being present in the dog's system. The X-ray will show a veterinarian the size, number and location of tumors present in the dog. A biopsy will be requested to determine if the cancer is malignant and likely to spread. There is a 50 percent chance of the tumor being malignant, according to Philibert.
Treatment
-
Treatment can vary depending upon the number of tumors and the size of the tumors. If there is a large number of tumors that have spread throughout the body, the condition is considered terminal and supportive treatment such as pain medication will be administered. If the tumors have not spread and the condition appears to be treatable, surgery will remove the large masses while chemotherapy and radiation can be administered to destroy the remaining cancer cells.
Prognosis
-
The prognosis of a dog with mammary gland tumors varies depending on the overall health of the dog and the severity of the tumors. If the dog is not in good general health and there are a large number of tumors that have infected the entire body, the prognosis is very poor and the condition may be considered terminal. If the dog is in good general health and the condition is caught early or the tumors are benign and not prone to spreading, the condition is treatable and full remission can be expected, according to Foster.
Prevention
-
The best way to prevent mammary gland tumors in a female dog is to have her spayed before her first heat, Foster advises. The chances of a female dog developing mammary gland tumors after being spayed before her first heat is .05 percent, while after the first heat but before the second increases her chances to 8 percent. Female dogs who are spayed after their second heat are 26 percent more likely to develop breast cancer, according to Foster. The dog spayed after her first heat should be fed a high-quality dog food and kept at an appropriate weight for her size and breed to reduce the risk of a mammary gland tumor.
-