Canine Mammary Cancer Symptoms

Dogs get breast cancer much the same way that human beings do. Female dogs that are likeliest to get breast cancer are unspayed bitches from five to 10 years old. Fortunately, if detected early, even the most aggressive forms of canine mammary cancers can be treated. Mammary cancer tumors are almost unheard of in dogs that are spayed before they go into heat the first time.

  1. Where Canine Mammary Cancer Symptoms Appear

    • Dogs have five mammary glands on each side of the body, on the lower abdomen. Each has its own nipple. The fourth and fifth nipples on each side (counting from front to back, the ones closest to the rear of the dog) are those likeliest to develop canine mammary cancer. One-half of canine mammary cancer cases are benign. Intriguingly, many of the cancer tumors in dogs are made up of multiple types of cells, which is different from most other species.

    Early Canine Mammary Cancer Symptoms

    • The earliest canine mammary cancer symptoms start out with small nodules near the teats, or with swelling and tenderness in the area. They can be detected by gently squeezing and rubbing the area around your dog's nipples--they'll often feel like small lumps of hard gravel or very firm flesh under the skin. Most will be firmly attached to the skin (your dog's skin fits more loosely than yours does; things that the skin doesn't move around are immediately suspect).

    Late Canine Mammary Cancer Symptoms

    • Nodules found early on can grow rapidly, doubling in mass (and size) roughly every month. If left untreated, they can result in ulcerations (places where the skin seeps blood), or interfere with the movement of the skin over the soft tissue of the abdomen. If left untreated, the cancer tumor cells can spread to the lymph nodes; the first three nipples will drain to the lymph nodes under the dog's forelimbs, while the more commonly cancerous nipples will drain to the lymph nodes near the hips.