This article was updated and revised in January 2026
What is mammary tumor in dog? Breast cancer is the most frequent neoplasm in whole (unsterilized) females. Unlike cats, in dogs about 50% of mammary masses are benign (fibroadenomas, adenomas) and 50% are malignant (carcinomas, sarcomas). Sterilization before the first heat reduces the risk to 0.5%, while after the third heat the protective effect wears off.
Symptoms of breast cancer in dogs
Often the nodules are discovered by chance by stroking the belly. Watch out for these signs:
- Single or multiple nodules: Balls that are hard to the touch along one or both mammary rows.
- Mobility: If the lump moves under the skin it is a good sign; if it is “glued” to the underlying tissues it is more worrying.
- Secretions: Fluid or blood leaking from the nipples.
- Ulceration: The skin above the lump breaks and bleeds (a sign of advanced malignancy).
- Edema: Swelling or warmth in the hind limbs (possible lymphatic blockage).
Cancer Udder Dog Survival
The onset of mammary cancer in dogs is facilitated by many pathological processes, it has been shown that the development of the oncological process in females is hormonal in nature. In this regard, the risk of developing mammary gland (TM) cancer in unneutered animals is significantly higher than in dogs neutered before the second estrus. In addition, mastitis, an inflammation of the mammary tissue in oncological practice, can be defined as a precancerous condition, since all these pathological processes can be a trigger in the development of mammary cancer in dogs. Dog Breast Cancer and survival depends on several factors:
- Size of the tumor (if greater than 4 cm, life expectancy is short)
- Dog Breast Cancer Stage
- Dog age
- Underlying or chronic health conditions and illnesses
The chance that the tumor is malignant increases with increasing size. The lymph nodes are usually affected when the tumor is larger than 5 cm. Invasion of surrounding tissues and ulceration are usually associated with malignancy.
Benign mammary tumors in dogs
Benign tumors are made up of several cancer cells and can contain both glandular tissue and connective tissue, they are divided into:
- Complex adenomas
- Fibroadenomas
- Papillomas ductus and simple adenomas
Malignant mammary tumors in dogs

- Tubular adenocarcinoma
- Papillary adenocarcinoma
- Papillary cystic adenocarcinoma
- Solid carcinomas
- Anaplastic carcinomas
- Breast osteosarcoma
- Mixed malignancies
Mammary Cancer in Dogs Treatment of Mammary Cancer in Dogs
The dog has five mammary glands, both on the right side and on the left side of its lower abdomen. Breast cancer can develop in all glands, but usually affects the fourth and fifth glands. It is very difficult to determine the type of tumor based on physical inspection, a biopsy is always needed to determine if the tumor is benign or malignant, and identify the type. The most aggressive tumors can metastasize and spread to the surrounding lymph nodes or lungs and for this reason a chest X-ray should always be taken.
Surgical removal remains the treatment of choice. Mastectomy can be partial (removal of only the affected gland), or radical mastectomy (removal of the affected gland and associated lymph nodes. Chemotherapy is not an effective treatment at the moment.
The oncologist will determine whether to intervene by removing the rest of the breast tissue and the lymph nodes that drain the gland in addition to the mass.
GOOD TO KNOW
- Chemotherapy is not a very effective treatment
- Radiation therapy has not been thoroughly studied
- Some hormonal drug therapies are in the experimental phase
The treatment tactic is chosen based on the stage of the oncological process, the growth of the tumor and the state of the lymph nodes. When widespread, the prognosis is considered poor. There are the following types of mastectomy
- Simple mastectomy: not used for therapeutic purposes, only as an option for an extended biopsy;
- regional mastectomy: removal of half of the ridge of the mammary glands with an adjacent lymph node;
- unilateral mastectomy: removal of the entire ridge and adjacent lymph nodes;
- Bilateral mastectomy: practically not used due to the impossibility of normal skin tension after surgery and major trauma.
The veterinarian must be experienced, he must adopt measures and techniques in which the possibility of dispersion of cancer cells is reduced to zero. During surgery, you will need to take steps to destroy any cancer cells that may enter your circulation. He must also observe the principle of “chance”, know the methods of lymphatic drainage.
Mammary tumor in dogs is inoperable

Natural Remedies and Integrated Cancer Support
The integrated approach and natural remedies do not cure cancer but help the body fight and reduce the effects of drugs and chemotherapy. Here are the pillars of the Elicats method:
- Low-Carb Feed: Cancer cells consume glucose 20 times faster than healthy cells. A fresh diet, low in carbohydrates (no rice, no corn) and rich in good fats and quality proteins is the first step to “starving” cancer.
- Synergistic Mycotherapy:
- Maitake & Reishi: To modulate the immune response without overstimulating it.
- Shiitake: Often used for its antiviral and general supportive properties.
- Specific Supplements: Apocaps or Luteolin, which act on cell apoptosis.
- Post-Anesthesia Detoxification: The use of milk thistle or homeopathic drainage remedies (e.g. Nux Vomica is vital after mastectomy to dispose of anesthesia.
Discover 30 Natural Remedies for Cancer in Cats
Chemotherapy aims to destroy cells, serves to prevent the occurrence of local recurrences (the onset of a tumor process at the site of its removal), as well as for the prevention of metastases and when mammary cancer in dogs is inoperable.
Dog mammary tumor recurrence
To reduce recurrences of dog mammary cancer , it is essential to support the dog from the outset with functional natural treatments and promote salutogenesis.
Frequently Asked Questions about Canine Mammary Cancer
How long does a dog with unoperated udder cancer live?
It depends on the nature of the tumor. If benign, the dog can live years without problems, until the mass becomes bulky. If malignant (carcinoma), the average survival without surgery varies from a few months to 1 year, depending on the aggressiveness and presence of lung metastases.
Does breast cancer in dogs break out?
Yes, fast-growing tumors can ulcerate (“burst”) due to poor blood supply to the skin stretched over the mass. This leads to infection and pain, making surgery urgent even for palliative purposes (for cleaning).
Can males have breast cancer?
Yes, although rare (less than 1%), mammary cancer also affects male dogs and is almost always malignant and aggressive.
Conclusion
The incidence of mammary cancer in dogs and cats can be significantly reduced with early sterilizations; This aspect is important both for the health of our dog and to avoid abandonment and uncontrolled litters.
Disclaimer: The Contents Are For Informational Purposes Only And Under No Circumstances Can They Constitute A Prescription Of A Treatment Or Substitute For A Specialist Visit Or Direct Relationship With Your Veterinarian/Doctor. All information reported here is derived from bibliographic sources, personal experiences and clinical studies in the public domain. The information disseminated on the site is published after careful verification of the sources, carefully chosen and as far as possible updated and official. All Information On Special Diets And Food Supplements For Pets Is For Informational Purposes. This information serves as a general guideline, it cannot be applied to all pets or considered as alternatives to professional advice. In these pages are inserted and presented alternative therapy and homeopathic remedies of unscientifically validated efficacy and without approved therapeutic indications. The products are not intended as a substitute for a varied and balanced diet and must be used as part of a healthy lifestyle. Disclaimer and Terms