Cancer: Tumors of the Stomach


The stomach is a dilated first part of the gastrointestinal tract that is a reservoir for food. This organ can stretch to accommodate a large meal. The stomach has a very powerful muscle that mechanically breaks down large pieces of food. In addition, the lining of the stomach secretes acid that digests proteins.

What is stomach cancer?

Cancer of the stomach comprises less than 1% of all cancers that dogs get, making it a relatively uncommon disease. There are many types of stomach cancer, however,  the adenocarcinoma is the most common type found. Adenocarcinomas can diffusely affect the stomach making it leathery and nondistensible. It may form a tumor that is a polyp with a narrow stalk. In other cases, the tumor may become ulcerated and cause the stomach to rupture.

Signs and diagnosis

Stomach tumors are most commonly seen in dogs that are between 7 and 10 years of age. The rough-coated collie, Belgium shepherd dog and Staffordshire bull terrier are predisposed to developing this type of tumor. In addition, males develop this tumor more commonly.

Signs of stomach cancer may include chronic vomiting, loss of appetite, and weight loss. Additionally, the patient may vomit blood, pass black tar-colored stools, and have abdominal cramps.

To diagnose this condition, x-rays following a barium swallow may be needed. X-rays of the chest should be made to look for signs of spread of the tumor into the lungs. Ultrasound of the abdomen may also be very useful to diagnose the presence of a mass in the wall of the stomach and can help identify enlarged lymph nodes and tumors in other organs. It is important to note that these imaging tests cannot identify microscopic spread of cancer to the lungs and internal organs. Endoscopy, which involves passing a flexible camera into the stomach via the mouth, allows direct visualization of the tumor and is a noninvasive method to collect a biopsy from the tumor.


Surgery will be recommended if there is no visible evidence of spread of the tumor. The stomach is exposed via an abdominal incision. The portion of the stomach affected by the tumor is removed and the stomach is reconnected to the small intestine. Biopsies of lymph nodes and liver may be done to rule out spread of the tumor. Most patients are hospitalized for 48 to 72 hours after the surgery.


At the time of diagnosis about 75% of all dogs will have spread of the tumor from the stomach. The median survival time of dogs that have surgical resection is 2 months (in 140 cases – from combined reports listed below) and the mean survival is 8.2 months. Currently, the benefit of chemotherapy following surgery or without surgery has not been investigated in the literature.

Learn more about this disease by contacting our Oncology service at your nearest BluePearl veterinary hospital. Here are our hospital locations.

© BluePearl Veterinary Partners 2012