Mammary tumours are often identified during a routine physical exam, or you may notice them at home. They usually present as:  

• A swelling of the mammary gland or around the mammary gland.  

• The swelling can be firm or soft and may be warm or painful to the touch.  

• Occasionally, the skin over the mass may ulcerate (open) and bleed, and the affected area may feel warm to the touch and become painful.  

• Your cat may tend to lick and groom the area excessively, and a strong odour can result as the exposed tissue becomes infected.  

If the tumour has metastasized (spread to other areas of the body), other signs may become evident. Your cat may generally feel unwell, eat less, become lethargic, and lose weight. If the lungs are involved, your cat may have problems breathing or develop a cough.  

As soon as you notice any lumps under your cat’s belly especially around her nipples, without delay.  

These tumours are typically found as either singular or multiple nodules along your cat’s abdomen during a physical exam. A common procedure to diagnose this tumour is a fine needle aspiration (FNA). FNA involves taking a small needle with a syringe to suction a sample of cells directly from the tumour and place them on a microscope slide. A veterinary pathologist then examines the slide under a microscope. In some cases, results from FNA may not be entirely clear and removal of the entire tumour may be necessary. Pieces of the tumour are then examined by a veterinary pathologist under a microscope. This is called histopathology. Histopathology is not only helpful in making a diagnosis but can also indicate whether it is benign or malignant and how the tumour is likely to behave.  

Given the risk of metastasis with malignant mammary tumours, your vet may also recommend staging (searching for potential spread to other locations in the body). This may include blood work, urine testing, X-rays of the lungs, and possibly an abdomen (belly) ultrasound and evaluation of the local lymph nodes.  

Surgery is by far the best treatment for cats with mammary tumours. Depending on whether there is a single mass present or several masses, a single chain mastectomy (removal of one side of the breast tissue) or double chain mastectomy (removal of both sides) will be performed.  

Depending on the tumour size and other factors, chemotherapy may be pursued afterward, which usually requires referral, especially given the high metastatic rate in these tumours.  

To dramatically reduce the risk of feline mammary cancer, female cats should be spayed before they enter their first heat cycle, or as soon as possible (approx. at 5-6 months of age).  

In addition, you as an owner can play a valuable role in recognising the presence of a mammary tumor at an early stage of its development by routinely touching your cat’s underside in the areas of the mammary glands and nipples. This should be done every week; the objective is to detect the formation of obvious masses or lumps of tissue when they are most treatable.  

Despite the fact that most feline tumours are aggressive and sadly pets may be terminal from this, early surgical intervention and possible chemotherapy can result in good control of disease for several months (depending on the type of tumour, prognostic factors, and response to treatment). Early detection is key to providing the best possible outcome.