Precision Medicine for Canine Mammary Gland Tumors

Mammary tumors are common in intact female dogs, especially middle-aged and older dogs of smaller breeds like Poodles, Chihuahuas, and Dachshunds, though some larger breeds are also at higher risk. Hormonal exposure plays a key role, with dogs spayed before their first heat cycle having only a 0.5% risk. Treatment typically involves surgical removal, which is potentially curative if the tumor is completely removed. For more invasive, advanced or metastatic cases,. Overall prognosis is quite variable depending upon key clinical features such as histopathologic subtype, tumor size, and metastasis.


Treatment Options

Treatment recommendations for mammary  tumors in dogs are often based on factors including grade, size, and metastasis. Surgery is often recommended as the first step in the treatment process because it removes the local disease but also provides valuable information about the tumor. In many cases, patients can do quite well if the tumor can be completely removed with surgery.

For high-grade tumors with evidence of vascular invasion or metastasis, systemic therapy is often recommended. Palladia, an oral anti-cancer drug that targets cancer cells based on a specific mutation, has also been used in the treatment of mammary tumors. Beyond Palladia, there have been additional targeted therapies that may be effective against mammary tumors identified through the FidoCure platform.

Although more extensive studies are needed, Adriamycin (Doxorubicin), a chemotherapy agent used in women with cancer, has shown promise in treating some canine mammary tumors. While generally well-tolerated, potential side effects include lethargy, decreased appetite, vomiting, diarrhea, and decreases in white blood cell and platelet counts. Some oncologists have explored the use of oral chemotherapy in addition to or as an alternative to Adriamycin for patients who do not tolerate injectable chemotherapy. Metronomic chemotherapy, a combination of oral chemotherapy and a non-steroidal anti-inflammatory drug (NSAID), aims to prevent cancer cells from developing their own blood supply and potentially delay disease progression.


With early identification and surgical removal, a significant number of canine patients can have a good prognosis with canine mammary tumors. However, patients that have more advanced or aggressive mammary tumors requiring additional therapy   may have a life expectancy of 6 to 12 months following diagnosis. Prognosis can be particularly poor for inflammatory mammary carcinomas or carcinosarcomas.

For the most accurate prognosis and treatment recommendations for your dog with mammary gland tumors, consult your veterinarian or a veterinary oncologist. They can provide personalized guidance based on your dog's specific case, considering factors such as cancer stage, grade, tumor location, and concurrent health issues.