Mastectomy

A mastectomy refers to the surgical removal of one or more mammary glands in dogs. The procedure is primarily used when tumours have formed in the mammary glands – unfortunately not uncommon in bitches. Such tumours can be benign or malignant. The aim of the operation is to remove the altered tissue and reduce the risk of spread (metastasis) as much as possible.

What is a mastectomy?

Depending on the findings, either individual glands are removed (partial mastectomy) or the entire mammary chain is removed at once (radical mastectomy). The glands lie in pairs in a row along the underside of the abdomen. Surgery is performed for malignant tumours – but also for benign ones that grow rapidly or damage surrounding tissue.

Reasons for a mastectomy

The by far most common reason is mammary gland tumours. Injuries or persistent infections of the mammary glands can also lead to this, but are significantly rarer.

Mammary gland tumours: Older, unspayed female dogs are particularly affected. Around 50% of mammary gland tumours prove to be malignant. In many cases, vets recommend a mastectomy to reduce the tumour burden and prevent further spread.

Chronic mastitis or infections: Occasionally, an inflammation of the mammary glands (mastitis) becomes so persistent that conservative treatments no longer work. In such – fortunately rare – situations, a mastectomy may become necessary.

Preventive measure: Sometimes the procedure is also considered as a precaution if a female dog has an increased risk of new tumours – for example, because benign changes have already been found in one gland and other glands could foreseeably be affected.

Preparation for a mastectomy

Before the procedure, the female dog is thoroughly examined. The aim is to assess its general health status and minimise the anaesthesia risk. Typically, this includes:

Blood tests: A blood count provides information on liver, kidney and heart values. If abnormalities are present there, the anaesthesia risk increases – this must be known before surgery.

Imaging techniques: X-rays or ultrasound of the chest and abdomen show whether the tumour has already spread to the lungs or other organs. Sometimes a CT scan supplements the picture.

Fine needle aspiration or biopsy: Before deciding on a mastectomy, a tissue sample is usually taken – either by fine needle aspiration or as a small biopsy – to clarify whether the tumour is actually malignant.

Ovariohysterectomy in unspayed female dogs: It is often advisable to perform an ovariohysterectomy (ovariohysterectomy) at the same time, as the risk of mammary gland tumours is significantly higher in intact female dogs.

Types of mastectomy

Which variant is chosen depends on how many glands are affected and how far the tumour has spread:

Partial mastectomy: Only the affected gland is removed. This option makes sense if the tumour is small and clearly defined.

Unilateral mastectomy: Here, the surgeon removes the entire mammary chain on one side of the body – including the adjacent lymph nodes. This is indicated if several glands on the same side are affected.

Bilateral mastectomy: If both mammary chains are affected, both sides must be operated on. This is usually done in two separate procedures so that the body can recover each time.

Course of the operation

The mastectomy is performed under general anaesthesia. An overview of the process:

The surgeon removes the affected gland – or several – and takes out a sufficiently wide margin of healthy tissue to ensure that as few cancer cells as possible remain.

In the case of malignant tumours, the adjacent lymph nodes are usually also removed, as tumour cells tend to spread there first.

The removed tissue is then sent to the laboratory. The pathological report confirms the type of tumour and provides information on the aggressiveness of the cancer.

To conclude, the wound is carefully closed; the female dog remains under observation until it has fully woken up from anaesthesia.

Aftercare following a mastectomy

The time after the operation is crucial for good healing. Key points at a glance:

Pain management: Painkillers and, if necessary, anti-inflammatory agents are part of the first few days. The vet determines the exact dosage.

Wound care: The suture site must remain clean and dry. Regular checks show early on whether an infection is developing. A protective collar prevents the female dog from licking or biting at the wound.

Physical rest: Keep it short in the first few days – short walks are sufficient, strenuous activities are off-limits. The body needs this period of rest to avoid jeopardising healing.

Follow-up examinations: Follow-up appointments with the vet are mandatory. Not only is wound healing checked, but the pathological report is also discussed, which is usually available a few days after the procedure.

Nutrition: A balanced diet supports regeneration. The vet can specifically recommend dietary supplements that promote the healing process.

Prognosis following a mastectomy

How good the outlook is depends on several factors:

Tumour type: If the tumour was benign, the chances are generally good. In the case of malignant tumours, it is crucial whether the tumour could be completely removed and whether metastases were already present.

Early detection: The earlier a tumour is discovered and operated on, the better the odds. Small, clearly defined tumours have a significantly better prognosis than large or already scattered ones.

Follow-up treatment: In the case of malignant findings, additional chemotherapy or radiotherapy may be useful to reduce the risk of recurrence. This is decided on an individual basis.

Prevention of mammary gland tumours

The most effective measure is considered to be early neutering – that is, neutering before the first or second heat. Bitches that have been neutered before their first heat develop mammary tumours less frequently; however, systematic reviews rate the quality of the underlying studies as low. This is a decision you should discuss with your vet at an early stage.