You might have no clue until it’s too late, but constant worry is the real terminal prognosis. Canine gastrointestinal cancer is a gruesome, silent killer, with dogs only showing symptoms when the disease has reached advanced stages.

Don’t freak out; canine gastrointestinal cancer is not at all common. It accounts for only 1 out of every 1000 cases of canine cancer. Nevertheless, you should stay vigilant and keep your dog healthy by feeding them a healthy diet, exercising often, and getting regular health checkups, especially if you have a breed like a Chow Chow, Akita, or Keeshond, among others.

The most common cause of stomach cancer in dogs is adenocarcinoma, a tumor of the glandular tissue that grows to reach the stomach and other vital organs. Below is an extensive breakdown of different types of gastrointestinal cancer in dogs and their tell-tale signs.


These are tumors originating from the mucous glands that line the digestive tract. Usually, this cancer spreads from glandular tissue to the liver, lungs, and pancreas among other organs. In the dog’s digestive tract, adenocarcinomas invade the small intestine, the large intestine, the stomach, and the rectum. It generally occurs in dogs older than six years. Adenocarcinomas affect all breeds of dogs indiscriminately and it is one of the most challenging tumors to diagnose and treat.

Mast Cell Tumors

Mast Cell TumorsMast cells are a part of the immune system. They are involved specifically in inflammation and responses to allergens. These cells are present in nearly all body tissues, but are more highly concentrated in the skin, in the walls of the digestive tract, and the nose.

In dogs, MCTs usually affect the skin, spleen, liver, and stomach. Breeds more likely to developed MCTs include Boxers, Boston Terriers, and Bulldogs.

When MCTs occur in the stomach, they cause the cells to release excess amounts of the biochemicals heparin and histamine which cause stomach ulcers and other autoimmune problems.


These tumors are specific to walls of hollow organs such as the stomach, the uterus, and the respiratory tract. This cancer often spreads to the lymph nodes, liver, spleen, and kidneys.


This type of cancer stems from lymph nodes and lymphocytes. Lymphomas can affect any tissue in the body, and the stomach is one of them.

Lymphoma is more common in dogs aged between 6 and 9 years old than in others. Breeds that are likely to be affected include Boxers, Bull Mastiffs, Basset Hounds, Saint Bernards, Scottish Terriers, Airedales, and Bulldogs.

Risk factors for canine gastrointestinal cancer

Risk factors for canine gastrointestinal cancerGender: Abdominal cancer is more prominent in males than females. Scientists are still researching why this is the case, as it is the same in humans.

Age: Canine cancer becomes a bigger risk as your dog ages. Canine gastrointestinal cancer is more prevalent in middle-aged to elderly dogs (eight years and older).

Breed: Studies show that breeds like Tervuren, Bouvier des Flandres, Groenendael, Collie, Standard Poodle, and Norwegian Elkhound are more predisposed to gastric carcinoma compared to other breeds. This is caused by the prevalence of a mutated gene.

Diet: Processed dog kibble with added nitrates and nitrites increase the risk of canine abdominal cancer. Studies show that when broken down in the digestive tract, these food preservatives produce carcinogenic compounds.

Signs and Symptoms of Canine Abdominal Cancers

Risk factors for canine gastrointestinal cancerThe signs of the above-listed canine gastrointestinal cancers are vague and difficult to detect. You should observe your pet closely if you notice frequent vomiting (with traces of blood) and drastic weight loss.

There are symptoms, however, that are more obvious. These include behavior changes due to abdominal pain. Your pet will wince in pain when you hold or touch him around the abdomen. He may eat only a little or not at all, and remain inactive for most of the time.

Other signs of canine abdominal cancer include anemia, lethargy, diarrhea, bloody stool, dark-colored stool, loss of appetite, and loss of sleep.


It can be hard to determine if your dog has canine abdominal cancer just from the symptoms outlined above. Blood and urine tests are needed for a proper diagnosis. X-rays of the abdomen are also essential, following a barium swallow test. If tumors from the abdomen have spread to the chest area, an x-ray can easily spot them.

An ultrasound test can be ideal to detect swollen masses, enlarged lymph nodes, and tumors in your pet’s abdominal area. These may be present in nearby organs such as the liver and spleen.

However, x-rays and ultrasounds may not be effective in the case of microscopic tumors that have spread in the abdominal organs. This is where an endoscopy can be useful. This procedure involves inserting a tiny camera into the mouth to look inside the stomach and intestines, allowing visual search for any abnormalities.


Surgery is generally recommended to remove the tumors. This, however, cannot be done in the case of lymphoma. In all other canine abdominal cancers, the stomach is bisected to remove the area affected by the tumor.

In some cases, tumors are so big that they block food from passing into the small intestine. Bypass surgery can be done here to offer symptom relief and help the dog live longer.

Radiation therapy is not suitable for canine abdominal cancers. This is because radiation can easily affect other vital organs close by including the liver and intestines. Chemotherapy has not proved useful in treating canine gastrointestinal cancers.

Nutritional Support

Drastic weight loss is a major problem in canines with abdominal cancer. A healthy diet will help to boost their immunity and improve their chances of survival, period. When a dog is severely underweight, their immune system becomes suppressed, which can cause them to succumb prematurely.


Canine gastrointestinal cancer is a cruel disease. Even with successful surgery, survival time is usually less than six months. This is mainly because abdominal cancers spread fast to nearby vital organs, causing a system collapse. However, remember that each case of canine gastrointestinal cancer is unique, and you might still have some time with your furry best friend.

It’s devastating to learn that your dog has stomach cancer. There are various treatments that you can use to reduce their pain and symptoms and help them live comfortably with the condition before they succumb to it. Whatever you decide to do, make sure you spend some quality, loving time with your pet.