What is malignant mammary tumors in cats?

Question

What is malignant mammary tumors in cats?

Answer 1

If you are familiar with breast cancer, then this is the feline form. Approximately 90% are malignant, with rapid spread to adjacent glands and the nearest set of lymph nodes. Cats generally have 8 mammary glands (thoracic, cranial abdominal, caudal abdominal, and inguinal – see illustration). The most commonly affected glands are the thoracic and inguinal glands. An owner should be accustomed to feeling for even small lumps in these areas. Because veins connect both the right and left sets of glands, it is easy for tumor cells to cross from one side to the other though usually the glands on the same side as the original tumor are seeded first.

At first the tumor is small and may feel like a pebble or dried pea. The tumor should be removed as soon as possible in hope of removing it completely. If left alone, mammary tumors get larger and harder and ultimately burst through the skin creating a smelly, infected ulcer.

Tumors spread from the mammary glands to local lymph nodes and then on to the chest, brain, bone, and even spleen. Expect chest radiographs to assess tumor spread to the lung to be needed before surgery can proceed. Basic blood tests will also be needed.