Did you know that more than half of all tumors found in female dogs are easily preventable? With a prevalence of greater than 26%, mammary tumors (breast cancer) are the most common tumors in female dogs who have not been spayed. However, when dogs are spayed before their first heat, the chance of developing mammary cancer drops to 0.05% (1 in 10,000 vs. 1 in 4). Dogs spayed after their first heat have an 8% chance of developing mammary cancer, and dogs spayed after their second heat have a 26% chance of developing mammary cancer. Pet owners who have no intention of breeding should spay their female dogs before their first heat to help control unwanted pet population and to help protect the long-term health of the dog.
Mammary tumors have been found in dogs as young as two years of age, but mammary cancer occurs most often in dogs between five and ten years of age. A female dog has ten mammary glands, each with its own nipple. Mammary tumors in dogs can develop in any of the glands / nipples, but it develops most often in the four glands / nipples closest to the tail. When mammary tumors first appear in dogs, they feel like small rocks under the skin. They feel hard to the touch and do not move around easily. Tumors may also feel like diffuse swelling. These tumors can metastasize and spread to the lymph nodes. Tumors that have spread to the lymph nodes can also be palpated (palpated means felt and detected by the hand). The lymph nodes most often involved are those at the top of the legs, the axillary and inguinal lymph nodes. Think of the dog as having armpits, and this is where you will find the lymph nodes in question. Owners can palpate the mammary areas and lymph node areas of dogs and cats periodically to check for the presence of tumors, but it is also helpful to have your veterinarian palpate the pet during routine wellness screenings.
The treatment for mammary cancer is surgery. If surgery is performed early in the course of the disease, the cancer can be fully eliminated in over 50% of the cases having a malignancy. Mammary cancers can grow and spread rapidly. The promptness of surgery greatly affects the prognosis. If you suspect mammary tumors in your dog or cat, call Healing Springs right away – this is not a wait and see problem.
Veterinary oncology is changing rapidly, and new therapies are becoming available at an impressive rate. For this reason, the vets of Healing Springs usually recommend a consultation with a board certified oncologist once a cancer diagnosis is made. This usually involves a trip to Carolina Veterinary Specialists or NC State in Raleigh. If the oncologist recommends chemotherapy or other treatments, the vets of Healing Springs can coordinate with the oncologist and administer and monitor the treatments locally.
Mammary Cancer in Cats: At 1 in 4,000, mammary cancer in cats is far less prevalent than mammary cancer in dogs. Unfortunately, when mammary cancer develops in cats, it is far more likely to be an aggressive, malignant variety with a poor prognosis. Up to 65% of mammary tumors surgically removed from cats will reoccur within 12 months. Cats who receive aggressive treatment on small tumors that were caught early sometimes live two to three years. As with dogs, spaying cats before the first heat cycle greatly reduces the chance of mammary cancer.