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Stomach Cancer in Dogs

Many cancers are life-threatening and this includes stomach cancer in dogs. It can either be benign or malignant and can greatly spread to other parts of the body.

"The estimated incidence rate is 20–100 cases per 100,000 dogs."

Learning that your precious fur-baby has stomach cancer can feel devastating, but it doesn't exactly mean it's the end of the world already. At the end of this article, you'll learn about the various types of cancer that attack the stomach, the signs your dog might display as well as proper management.


Your fur-baby's gastrointestinal tract is consists of many different organs. The GI tract runs from the mouth to the anus. This tract functions to be able to digest food and properly absorb nutrients to be distributed all throughout the body.

The stomach is also a part of the GI tract that helps in the digestion processes. This extends to the small intestines, the colon that further breaks food into absorbable nutrients.


The exact causes of stomach cancer in dogs is unknown. But factors like age, lifestyle, diet, poor nutrition, genetics, etc. can pre-dispose your fur-baby into developing one.

Other dog breeds, too, are more prone than others. These breeds include Staffordshire Bull Terriers, Chow-chows, and Belgian Shepherds. Senior dogs are also more at risk.


Lymphoma. This cancer begins in your dog's blood, in the white blood cells to be exact. Though lymphomas do not commonly affect the GI tract, in rare cases these tumors can be found in the stomach. The estimated incidence rate is 20–100 cases per 100,000 dogs.

Adenocarcinomas. This type of stomach cancer often begins in the glandular tissue (produces digestive juices to help breakdown food) and has the tendency to spread to other body parts like the liver and the lymph nodes. One study reported a male-to-female ratio of 17 : 7 for adenocarcinomas. Male dogs are more prone to this type of stomach cancer.

Leiomyosarcomas. This type of cancer is in the form of tumors and often begins in the walls of the bladder, uterus, respiratory tract, and yes, the stomach. It only occurs in 35 out of 100,000 dogs, according to the National Canine Cancer Foundation (NCCF).

Mast Cell Tumors. For the record, mast cells are actually part of your fur-baby's immune system. It functions whenever the body is inflamed or reacts to allergies. These cells are present in many different body parts like the nose, skin, lungs, and the GI tract. Cancer forms when these mast cells turn abnormal and create tumors. These tumors actually release excessive amounts of the natural chemicals histamine and heparin (naturally produced by normal mast cells) and cause an overdose in your dog's body. Mast cell tumors are relatively common, about 90 dogs for every 100,000 dogs in any year, according to Kingsbrook Animal Hospital.


Stomach cancer in dogs is silent because signs and symptoms only begin to show by the time the cancer is already in its late stages.

Vomiting. If your dog has stomach cancer, vomiting can be one of the first symptoms you'll take note of. Sometimes, your dog's vomiting can even include blood and because the GI tract is all out of control, your dog's body will be unable to digest food properly and absorb nutrients, leading to malnutrition, weight loss, and weakness.

Extreme pain. As expected, any type of cancer brings pain. You will notice how uneasy your dog will become and may exhibit constant signs of discomfort like suddenly crying and whining.

Recurring sores. Sores can be normal for some dogs, especially for those who have skin allergies. But recurring sores that don't seem to get better are unusual. Stomach cancer in dogs can also be about wounds that don't seem to heal at all even with treatments.

Presence of unusual lumps and swellings. One of the most recognizable signs of cancer is a mass or a lump or a bump that grows under the skin, particularly in the stomach area.

Appetite loss. Since your dog's GI tract functioning is a total mess adding any presence of a tumor, it will keep on pushing along the intestines that will make your dog feel unwell and bad. This discomfort and pain will prevent your dog from having the urge to eat anything.

Energy loss. Cancer cells make use of glucose from carbs to form lactate. Lactate is difficult to absorb by the body that's why your dog will spend additional energy trying to turn lactate into a useful form. What a dramatic waste of energy.


As said, stomach cancer in dogs can be life-threatening but it certainly isn't the end of the world yet because you can actually do so many things to help your dog recover or at least make his life a little bit better.

Consult your vet. If you notice two or more of the primary signs mentioned above, it is time you go and see your vet. Your vet will perform tests on your dog to know what exactly he's going through. If tumors or abnormal masses are present in the GI tract or in the stomach, it is a probability that your vet will suggest to have it removed so that he can have it undergo a biopsy to determine whether it's cancerous or not.

Chemo. And if the results end up positive for cancer, there are actually chemotherapies available for dogs. But note that radiation can be harmful to your dog as it can have tremendous effects on sensitive organs surrounding the stomach.

Nutritional support. Weight loss is common to any dog who is suffering from cancer. Being underweight, too, weakens the immune system. If your fur-baby is going through cancer treatment, it's always important to provide him the proper nutrition his body needs to gain his weight and health back.

Alter your dog's diet... with your vet's approval of course. Stomach cancer will create a number of metabolic changes in your dog's body. His old diet may or may not be suitable for him anymore, considering all other interventions like the medicines he's taking, the severity of cancer, etc.

Provide essential oils. Providing your dog food and supplements with essential oils like omega-3 and omega-6 will help strengthen his immune system and repress tumor growth.

Administer Vitamin C. Know to have antioxidant properties, Vitamin C is good for your dog. It helps fight off free radicals and boosts your dog's immunity, too.

Give Probiotics. Probiotics will greatly help your dog's stomach in getting back to its shape. Probiotics consist of live microorganisms that may help synthesize important hormones that can support a fur-baby's body system and help balance out the helpful and harmful bacteria.


Choosing the right supplements for your dog with stomach cancer can be overwhelming, but high-quality ones (just like the ones from Pet Parents®) will not give you any second thoughts.

Pet Parents® Omega Supplements have anti-inflammatory benefits. Every dog should be on an omega 3 fatty acid supplement.because it has been presented to help aid in decreasing inflammation and benefit organ function.

Also, Pet Parents® Probiotic Supplements have Proprietary Probiotic Blend (Lactobacillus acidophilus, Lactococcus lactis, Lactobacillus plantarum, Lactobacillus fermentum, Lactobacillus brevis). A powerful Probiotic Blend that supports good bacteria to improve digestion & nutrient absorption and strengthen immune function. It also helps in promoting good gastrointestinal health. Please note supplements are not the cure all, but they can assist with overall health.

Stomach Cancer in Dogs

" Every dog should be on an omega 3 fatty acid supplement.because it has been presented to help aid in decreasing inflammation and benefit organ function. "

While cancer can be stressful to deal with, there is no reason to go all-out crazy and paranoid. Stay informed, observe your dog, talk to your vet, show your dog how much you love him. By doing so, it will help you and your fur-baby live a healthy and happy life.

The Author:

Micka V.

Micka Virtudazo is a full-time content creator at Pet Parents who lives with thirteen adorable American Bullies and a Shih Tzu-Maltese mix named Gretel. She especially enjoys writing how-to articles as she feels through this she can connect to other pet parents on a more personal level.

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