Long-Term Stomach Inflammation in Dogs

Chronic Gastritis in Dogs

Chronic gastritis is the term used for intermittent vomiting of greater than one to two weeks caused by inflammation of the stomach. The stomach lining can be irritated by chemical irritants, drugs, foreign bodies, infectious agents, or long-term hyperacidity syndromes. Long-term allergen exposure, or immune-mediated disease (where the body's own anti-bodies attack the tissues of the body) may also produce long-term inflammation of the stomach’s lining.

Old, small-breed dogs like Lhasa Apsos, Shih-tzus, and Miniature Poodles are more commonly affected with long-term gastritis. But larger breeds such as the Basenjis and the Drentse Patrijshond can also develop long-term gastritis.

Symptoms and Types

  • Diarrhea
  • Weight loss
  • Black, tarry stools
  • Green-stained vomit (from bile from the gallbladder) containing:
    • Undigested food
    • Flecks of blood
    • Digested blood “coffee ground” appearance

The frequency of vomiting may also increase as the stomach inflammation progresses. This can occur early in the morning or be induced by eating or drinking.


Chronic gastritis is ultimately caused by inflammation of the stomach. Underlying factors that may induce this include:

  • Eating inappropriate things/foods
  • Adverse drug/toxic reaction
  • Metabolic/endocrine disease within the body
  • Infections (e.g., bacterial, viral, parasitic) 


Your veterinarian will perform a thorough physical exam and order blood work: a chemical blood profile, complete blood count, and urinalysis. The blood work will tell your veterinarian how dehydrated your pet is, how much blood your pet has lost, if the disease is long-term, if the disease is caused by a faulty immune system or liver disease, if your pet has ulcers, or if your pet has some other disease of the organs causing the stomach inflammation.

Abdominal X-rays, contrast X-rays, and an abdominal ultrasound will help to determine the underlying cause of the stomach’s inflammation. A biopsy of the stomach is essential for diagnosis. A fecal floatation should also be done to check for intestinal parasites. Surgery may be required in some cases, and an endoscopy can be performed to remove foreign objects and to take samples of the stomach.

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