A stomach (or gastric) tumor can be defined as rapid reproduction or abnormal cell growth within the stomach. Most of the time, tumors in the stomach emerge from the cells of the stomach’s inner lining or the muscle found around the lining. They may be classified as either benign or malignant, but most are malignant (cancerous). Unfortunately, malignant tumors are invasive and are prone to metastasizing.

Like humans, dogs can get stomach tumors too. While stomach tumors in dogs are rare (accounting for less than 1% of malignancies in dogs and cats), they're possible.

Examples of stomach tumors in dogs include adenocarcinomas, lymphomas, leiomyomas, leiomyosarcomas, mast cell tumors, plasmacytomas, gastrointestinal stromatolite tumors (GISTs), and fibrosarcomas. Although rare, dogs may also get benign adenomatous polyps.

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  1. What Causes Stomach Tumors In Dogs
  2. What Are the Signs Of Stomach Tumors
  3. How Do Vets Treat Dog Stomach Tumors
  4. How Can the Emergency Fund Help with Treatment
  5. FAQs
  6. Conclusion

What Causes Stomach Tumors In Dogs

How do dogs get tumors in their stomachs? The cause behind a stomach tumor in a dog, as with any type of tumor or cancer, is not quite clear. However, most tumors seem to be caused by a complicated blend of risk factors, including genetic, hereditary, or environmental factors.

With stomach tumors in particular, it seems that breed, age, and sex are possible indicators of their emergence. Older dogs seem to be more susceptible to it. Also, males appear to have a higher risk, whether the tumor is malignant or benign.

Among the dog breeds that seem to be more prone to stomach tumors are Chow Chows, Beagles, Norwegian Lundehunds, Staffordshire Terriers, Dutch Tervueren Shepherds, and Rough Collies. In addition, exposure to nitrosamines (a chemical contained in many foods) via long-term feeding has been associated with gastric adenocarcinoma.

What Are the Signs Of Stomach Tumors

Malignant stomach tumors in dogs have symptoms that usually come gradually over weeks or months. The most common and oftentimes the first symptom to appear is chronic and intermittent vomiting, which may appear to be tinged with blood or may look like coffee grounds as the disease spreads. This is brought about by the tumors ulcerating. Another effect of this is that your dog’s stool may appear black, indicating the presence of blood.

Other symptoms of stomach tumors in dogs that you should look out for include:

To better look out for symptoms of stomach tumors as well as other symptoms that are out of the ordinary, a pet camera such as the Pet Camera may come in handy. This allows you to monitor your dog 24/7, even if you’re away during the day. It makes it easier to detect the symptoms early on and thus be able to address them.

How Do Vets Treat Dog Stomach Tumors

Treating stomach tumors in dogs depends on the tumor type as well as how advanced or aggressive it is. The options may include surgery, chemotherapy, radiation, or a combination of the said treatments.

  • Surgery
    If possible, this is usually the first course of treatment recommended to remove tumors in a dog’s stomach. When the tumors have metastasized, removing them through surgery is oftentimes palliative to help reduce the symptoms and improve your dog’s quality of life. The long-term prognosis is not looking good. However, surgery can provide relief for a few months before the growths cause problems or regrowth of the tumor occurs. Meanwhile, chemotherapy may be done after the surgery in some cases.

  • Chemotherapy
    With or without surgery, malignant stomach tumors in dogs may be treated with chemotherapy to help prevent them from spreading to other parts of the body. Unlike us humans, dogs who undergo chemotherapy rarely lose their hair. In addition, they experience fewer side effects from the treatment.

  • Radiation therapy
    This treatment may be recommended when the tumors are localized and cannot be removed through surgery.

How Can the Emergency Fund Help with Treatment

A Pet Emergency Fund will definitely help you with the treatment of a stomach tumor in your dog. Because treatment for the condition can be very expensive due to the complicated nature of the disease, having a pet emergency fund allows you to treat your dog without worrying about whether you can afford it or not. It is a complicated disease, and having the assurance and peace of mind that your dog will be given the proper treatment to improve their quality of life goes a long way.


How long can a dog live with a cancer tumor?

This would depend on the kind of tumor, how advanced it is, and how fast it spreads. Upon diagnosis, some dogs may live for a few weeks or a couple of months. On the other hand, others continue to live for years.

What is the prognosis for a dog with a large abdominal tumor?

This prognosis would depend on the location of the tumor in the stomach. For example, many dogs that get gastric adenocarcinoma have a life expectancy of 6 months after surgery. Meanwhile, the median survival period for dogs that have small-intestinal adenocarcinoma is between 4 and 18 months.


When your dog is diagnosed with stomach tumors or cancer, it can be overwhelming. However, equipping yourself with information will help you make decisions about treatment down the line. Meanwhile, Your veterinarian may help guide you toward the best treatment plan for your dog.

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