This article was updated and revised in January 2026
What is mammary cancer in cats?
Mammary cancer is one of the most common neoplasms in older cats, especially in unspayed females. Unlike dogs, these tumors are extremely aggressive in cats: about 85-90% of feline mammary masses are malignant (carcinomas) and tend to quickly metastasize to the lymph nodes and lungs. Early diagnosis is the only factor that significantly increases life expectancy.
It is the third most common cancer in cats. The average age of onset is around 10-11 years, and the risk increases with increasing age up to 14 years.
- Almost 90% of breast cancers are malignant
- They appear as firm nodules, firmly attached to the skin and/or muscle underneath
- The Siamese breed has a two-fold higher risk of developing breast cancer
How to recognize breast cancer: Symptoms
Don’t wait for the lump to grow large. Here are the warning signs to look for during cuddles:
- Subcutaneous nodules: Small hard balls near the nipples (may look like grains of rice).
- Ulceration: Wounds on the belly that do not heal and bleed.
- Excessive licking: The cat obsessively cleans its abdominal area.
- Swelling and redness: The area around the nipple appears hot and inflamed.
- Systemic symptoms (advanced stage): Weight loss, coughing (lung metastases) and lethargy.
Initially the mammary gland has one or more soft nodules, gradually the nodules harden and increase in size. This process usually takes place after estrus. You may notice enlargement of the regional lymph nodes around the tumor, alopecia and ulcers. Mammary cancer in cats is almost always malignant.
Mammary tumor in the cat mammary glands
MAMMARY GLANDS
Cats have four pairs of mammary glands
- Thoracic
- Cranial abdominal
- Caudal abdominals
- Inguinal
The glands most affected are those in the thoracic and groin area.
Mammary cancer in cats: how long can it survive?
The prognosis (statistics) depends on several factors, such as the age of the cat, other ongoing diseases, immune status, lymph node involvement.
- When the tumor is treated surgically, and the size is less than 2 cm in diameter, cats can have a survival of about 4 years
- When the tumor reaches a size greater than 3 cm in diameter, the average survival time is about 6 months.
Natural Remedies to Support Breast Cancer
In addition to surgery (mastectomy) and chemotherapy, the integrated approach is crucial to support the feline immune system.
- Mycotherapy (medicinal mushrooms):
- Maitake (Grifola Frondosa): It is designed for its ability to stimulate Natural Killer cells and induce apoptosis in breast cancer cells.
- Coriolus Versicolor: Essential to support the body during traditional treatments.
- Ketogenic/Low Carb Feeding: “Starving cancer” by drastically reducing dry carbohydrates in favor of high-quality protein wet food.
Discover 30 Natural Remedies for Cancer in Cats
Mammary Cancer in Cats Stages of the Disease
In cats, 4 stages of the development of the malignant process are distinguished:
- Stage zero: a tumor less than 5 mm in size;
- The first stage is a tumor up to 2 cm in diameter without metastasis;
- The second stage: a tumor with a diameter of less than 3 cm, without metastases;
- The third stage is a tumor larger than 3 cm without metastases or less than 3 cm with metastases to regional lymph nodes;
- The fourth stage is a tumor with a diameter greater than 3 cm with damage to the regional lymph nodes; a tumor of any size in the presence of distant metastases; inflammatory carcinoma.
The symptoms of a mammary tumor in cats in the early stages do not appear. An exception is neoplasms that have the shape of small nodules and are located in the abdomen. Unfortunately, most owners don’t notice these changes. Signs of a malignancy:
- Stage I
The size of the tumor ranges from 0.3-0.5 to 1-1.5 cm When probing the abdomen, a slight “granularity” may be felt. At this stage, the animal is not bothered by pain. Its activity remains and appetite is normal.
- Stage II
Neoplasms are rapidly increasing in size – up to 2-3 cm New foci, not yet enlarged, can be palpated on nearby mammary glands. However, the animal’s condition is normal, it does not feel discomfort.
- Stage III
The size of the neoplasms ranges from 3 to 5 cm. The behavior and mood of the animal are changing. More often than not, he is in a depressive state, refusing food. When probing the abdomen, it reacts painfully. There is a smell of ammonia.
Cat ulcerated mammary tumor
- Stage IV
Ulcerated mammary tumor in cats grows noticeably, begins to penetrate nearby tissues. There is an unpleasant smell. The animal’s condition worsens, there is weight loss and difficulty breathing. The prognosis and probable outcomes of the disease depend on its stage: stage zero and stage one cancer is curable in the vast majority of cases, in the second stage the prognosis is often favorable, in other cases it is rarely possible to cure the cat completely, but the treatment is still carried out in order to prolong the life of the animal. However, in some cases in the fourth stage, the feasibility of surgery and chemotherapy may be questionable, in such cases maintenance therapy is performed.
Mammary Tumor Cat Survival
Survival in the case of mammary cancer in cats depends on the staging and type of tumor, whether benign or malignant. In cats, unlike dogs, benign tumors of the mammary gland are very rare (according to various estimates, no more than 20% of the total number of neoplasms detected).
The average survival time is closely related to the involvement of local lymph nodes;
It is always advisable to take x-rays to rule out metastases to the lungs
Non-specific clinical signs
- Weight loss
- Lack of appetite
- Lethargy
- Exercise intolerance
- Dyspnoea (caused by lung metastases)
Mammary Tumor in Cats Cytology
Mammary Tumor in Cats Cytological Examination: This study is based on the analysis of the cellular composition of the contents of the tumors and adjacent tissues. The material is taken by piercing the tumor with a needle in several places. Cytological examination is less invasive than, for example, histological examination, but its accuracy is much lower, therefore it is not used for all cats with mammary tumors, but only if there are indications for its implementation.
Mammary Tumor in Cats Histological Examination
Mammary tumor in cats Histological examination: The tumor and adjacent tissues removed during the operation are subject to histological examination. Unlike a cytology study, tissue sections are evaluated, not individual cells, so the accuracy of the conclusion is higher. The histological examination makes it possible to determine the type of tumor, the stage of the disease and whether the affected area was completely removed during the operation.
Mammary Tumor in Cats Mastectomy Surgery
Surgical techniques for removing mammary tumor in cats include partial mastectomy, regional mastectomy, unilateral mastectomy, bilateral mastectomy, and radical mastectomy. The surgical choice depends on the location and size of the breast tumors.
Mammary tumors in cats are often malignant and highly metastatic, many cats that develop mammary tumors quickly develop other tumors, therefore it is necessary to consult a veterinary oncologist to be sure that all the mammary tissues involved are removed, where possible it is preferable to proceed with a gradual mastectomy Over the course of 4-6 weeks, this prevents the cat from having a lot of post-operative pain and a slower recovery in a single surgical procedure. It should be remembered that the cat can have both malignant and benign masses.
Treatment consists when possible, in the surgical removal of the cancerous tissue, it is advisable to start immediately in agreement with the veterinarian functional and complementary therapies to support the immune system.
Mammary tumor in cats post-operatively, how to help the cat
Most cats are discharged after 2-5 days, depending on the extent of the intervention and the recovery of the cat, the pain can be well controlled with medication even at home.
Cancer in cats pain in cancer cats.
After surgery the return home: Buy the Elizabeth Collar to use for 10-14 days after surgery to prevent the cat from having access to the wound and stitches, I recommend the purchase of a soft and very comfortable foam collar like this
Limit physical activity for at least 2 weeks, it is recommended to let the cat stay in a quiet place, free of noise, litter box and bowls close together and a low and wide kennel, even the litter box should not have very high edges, a litter box on newspaper is useful. In case you have to spend a lot of time outside the house and leave the cat alone (not recommended) it is preferable to equip yourself with a medical onesie for cats, this protects the area well and is not very tight. (check size and measurements)
Postoperative complications may include:
- Infection (check the wound daily)
- Opening or rupture of the wound
- Local tumor recurrence or tumor spread that was not detected at the time of surgery.
If the breast tumor is malignant, the surgical site and regional lymph nodes should be checked every 3 months for the first 12 months after surgery and every 6 months thereafter. Abdominal ultrasounds and chest radiographs every 3 to 6 months are also recommended to assess evidence of metastatic disease.
Frequently Asked Questions about Feline Breast Cancer
How long does a cat with mammary cancer live?
Life expectancy depends on the size of the tumor at the time of diagnosis. If the lump is less than 2 cm, survival can exceed 3 years. If the tumor is greater than 3 cm or there are metastases, the average survival is reduced to 4-6 months without treatment.
Is mammary cancer in cats painful?
In the early stages, lumps are usually not painful. However, if the tumor grows rapidly, ulcerates or becomes infected, it becomes very painful and requires immediate pain management with drugs and natural remedies such as Arnica or Boswellia.
Should an elderly cat be operated on for mammary cancer?
Age is not a disease. If blood and heart tests are good and there are no visible metastases to the lungs, surgery (mastectomy) is often recommended to improve quality of life and prevent ulceration of the tumor, even in cats as young as 12 to 14 years old.
rev2026
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. All information on special diets and dietary supplements for pets is for informational purposes. This information serves as a general guideline, cannot be applied to all pets or considered as an alternative to professional advice. These pages include “Homeopathic preparations of non-scientifically 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
