Breast cancer in dogs | Daily News


Breast cancer in dogs

Mammary (or breast) cancers are common in female dogs, but rare in male dogs and cats. Of dogs, poodles, dachshunds, spaniels and in cats, Siamese are most affected. In dogs, obesity at a young age is a risk factor. Most of unspayed female dogs will develop a mammary cancer during their lifetime.


A palpable mass underneath the skin of the abdomen is the most common findings in dogs and cats with mammary cancer. However, other signs and symptoms include discharge from a mammary gland, ulceration of the skin over a gland, painful, swollen breasts, loss of appetite, weight loss, and generalized weakness.


A good general physical exam is needed to find the location, size, and character of all the mammary masses and assess local lymph node enlargement.

Other procedures are Bloodwork: blood count, chemistry, urinalysis, and clotting profile, Abdominal ultrasound, chest x-rays and sometimes CT scan: used to check for cancer that has spread to other parts of the body, Aspiration: a needle is used to sample the mammary mass to help distinguish it from other skin tumors.

Lymph nodes may also be assessed to look for a spread of cancer cells. This is more reliable in dogs than cats to confirm a diagnosis.


Surgical removal is recommended for most mammary cancers. The type of surgery depends on the size, location, and number of mammary cancers and species of your pet. In general, surgery is more conservative for dogs with mammary cancers and involves removal of either the mass alone or the affected mammary gland.

However, in cats, more aggressive surgery is recommended with removal of one or preferably both sets of mammary glands

Chemotherapy may be required following surgery in some cases. The prognosis is good following surgical resection for most mammary cancers in female dogs, but the prognosis is worse for certain types of cancers in dogs and all mammary tumors in cats.

For most mammary cancers in cats and dogs, hormonal therapy, immunotherapy, and radiation therapy have either not been investigated or are not beneficial.

After care

Most pets are discharged 1–5 days after surgery, depending on their extent of surgery and their comfort. They are usually returned for re-check and removal of skin sutures or staples. Pain can be well-controlled with owner-administered medications.

Postoperative complications can include: Incision infection, Incision opening or breakdown, which is more common in the mammary glands near the back legs or when larger areas of tissue have been removed, Local recurrence of the tumor or spread of the cancer that was not detected at the time of surgery.

In dogs, there are a number of factors that influence the prognosis following surgery. These prognostic factors include cancers size, clinical stage, tumor type and grade, and various other pathologic changes seen in the cancers tissue.

Mammary cancers can be largely prevented by spaying before 6 months of age or before your pet’s first heat cycle. Other factors that may reduce the incidence of mammary cancers include feeding a well-balanced diet and avoiding obesity and the administration of hormones

(The writer is a Veterinary Surgeon and holds B.V.Sc; M.Sc Poultry Science; Master of Public Administration and Management)

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