Mammary tumors are malignant (cancerous) or benign (non-cancerous) growths in the breast tissue. This type of tumor develops when the cells of the mammary gland (breast) replicate uncontrollably.
Certain breeds of pet have been shown to be at higher risk of developing mammary tumors. These include Siamese cats, cocker spaniels, and poodles. Female dogs are most susceptible to the condition. However, many mammary tumors in female dogs are benign, and the prognosis following treatment is usually good.
Although far less common, mammary tumors in cats and male dogs are often malignant and pose a serious threat to health.
Causes of Mammary Tumors
The exact cause of mammary tumors is unknown, but contributing factors are thought to include genetics, hormones, and exposure to carcinogenic chemicals. Obesity may also play a role in the development of this type of tumor.
Symptoms of Mammary Tumors
Mammary tumors can be serious and potentially life-threatening. Please visit your veterinarian immediately if your pet displays any of the following signs or symptoms.
- Single or multiple masses underneath the skin of the abdomen
- Discharge from the mammary glands
- Ulcerated or bleeding skin
- Inflamed nipples
- Loss of appetite
- Weight loss
- Lethargy
Diagnosis of Mammary Tumors
Your veterinarian will assess your pet’s medical history and ask you a series of questions about the onset of their symptoms. They will then perform a thorough physical examination to check for clinical signs of mammary tumors.
Bloodwork, a urinalysis, and other diagnostic tests may be used to evaluate your pet’s overall condition and rule out other causes of their symptoms. If there is evidence of mammary tumors, a tissue biopsy or fine-needle aspiration will be used to check for malignancy. Your veterinarian will also use imaging techniques such as X-rays or ultrasounds to check for the spread of malignant growths.
Treatment of Mammary Tumors
Your veterinarian will consider several factors including the size, location, and the number of tumors before deciding on the best course of treatment. In most cases, surgical removal of the tumors will be required.
If tumors are malignant, your veterinarian may also recommend removing surrounding tissue or the entire affected mammary gland. In some cases, the lymph nodes may need to be removed to prevent the spread of cancerous cells.
Chemotherapy or radiation therapy may also be used, alone or in conjunction with surgery. After initial treatment, medications such as antibiotics and painkillers will usually be prescribed to aid the healing process. It is very important to follow your veterinarian’s treatment advice fully to give your pet the best chance of recovery.
Prevention of Mammary Tumors
The best way to prevent mammary tumors is through early spaying of female pets. Ideally, the procedure should be performed before the animal enters its first heat cycle. Please speak to your veterinarian for more information about the benefits of spaying.
