Canine Stomach Cancer

Causes of Cancer in Dogs

There are several different types of cancers that are associated with stomach cancer in dogs.

Adenocarcinomas

Adenocarcinomas are the type of tumors most often associated with cancer of the stomach. This cancer is one that is found in glandular tissue. This cancer will often spread to the liver, lungs, and lymph nodes.

Mast Cell Tumors

Mast cells are part of the immune system that have a role in inflammation and allergic responses. These cells are present in the linings of the digestive tract, lungs, nose, and skin. When mast cells become abnormal, they often form mast cell tumors. The tumors release excess amounts of the biological chemicals heparin and histamine which are normally produced by mast cells. This overdose of natural chemicals damages the body.

Leiomyosarcomas

Leiomyosarcomas are tumors that form in the walls of hollow organs such as the stomach, bladder, uterus and respiratory tract. The gastrointestinal tract is the organ that is most often affected by these tumors. This type of tumor, when found in the gastrointestinal tract, will often metastasize to the lymph nodes and liver. It can also spread to the spleen and kidneys.

Lymphomas

Lymphoma is a type of cancer that begins in white blood cells called lymphocites. Although lymphomas are not the most common cause of stomach cancer, these tumors can be found in the gastrointestinal tract. Dogs around the age of eight are most affected by this type of cancer.

Breeds that are most often affected are:

• Boxers
• Saint Bernards
• Mastiffs
• Airedales
• Bulldogs
• Scottish Terriers

Symptoms of Canine Stomach Cancer

Vomiting

Vomiting is often the first symptom of canine stomach cancer. It is also the most common, and there should be special concern if the vomit has blood in it. Often due to poor digestion, the dog will experience weight loss and lethargy.

Pain

Cancer of the gastrointestinal tract will usually cause pain for the dog. Addressing pain should be part of the treatment plan in addition to treatment of the cancer and other symptoms. Dogs are not always obvious about being in pain; many of them put on a brave front and are quite stoic. Some of the signs that a dog is in pain are:

• Lower activity level
• Less social
• Not willing to move
• Vocalization (whining, growling)
• Decreased appetite
• Reacts to being touched in an unusual way (yelping, snapping running away)
• Increased respiratory rate
• Inappropriate elimination (urinating or having bowel movements indoors)
• Unhappy demeanor and body language
• Scratching or repeated licking of a particular body part

Treatment

If the cancer has not metastasized, surgical removal of the tumor is the most common and beneficial way to treat stomach cancer. This is the case with most tumors except lymphomas. If the tumor is preventing food from entering the stomach, bypass surgery is often helpful to the health of the dog, even though this surgery does not treat the cancer itself. Chemotherapy does not seem to be effective for cancer in the stomach. Radiation is dangerous to the delicate organs near the stomach and is rarely considered and option as a treatment for stomach cancer.

Nutrition

Severe weight loss is a common problem among dogs with cancer. A diet that is especially created for a dog going through cancer treatment will be critical for maintaining his overall health and quality of life. Being severely underweight negatively affects a dog's ability to withstand cancer treatments and also suppresses his immune system.

Prognosis

Dogs diagnosed with malignant stomach cancer do not have an optimistic prognosis. Most dogs do not live beyond six months even with treatment. This is largely due to recurrence of the cancer or spread of the tumors to other organs. It is best to understand your dog's individual situation by discussing this diagnosis with his veterinarian.