Stomach Ulcers in Dogs and Cats

The stomach is an important component in an animal’s digestion process. It produces acid and activates enzymes responsible for the digestion of food. Because of the high acidity of gastric juices, the lining of the stomach is specially built to withstand a low-pH environment with minimal damage. The mucosal lining of the stomach produces mucus that helps protect the surface from inflammation, irritation, and damage from the gastric acid it produces.

The Stomach’s Protective Barrier and How Ulcers Form on It

The stomach’s outermost lining primarily consists of mucosal cells producing a mucus barrier on top of it. This mucosal barrier protects the underlying layers where most functional gastric cells responsible for producing gastric acid are located. The mucosal barrier mostly contains alkaline molecules to help neutralize the acidity of the gastric fluid. This outermost mucosal layer is also highly vascularized and has a high blood flow to help clear out gastric acid that diffuses into the gastric surface. This efficient blood flow also helps stimulate the rapid renewal of injured cells on the surface.

This defense mechanism of the stomach’s outer lining helps balance out any damaging properties of the stomach acid, and sometimes intestinal, contents. However, certain conditions, medications, and health conditions disrupt the gastric mucosal barrier and predispose the stomach to damage and injuries.

Any defects to the protective barrier allow hydrochloric acid and other digestive enzymes to come in contact with the mucosal and epithelial cells, causing damage and injury. As the stomach lining becomes damaged, inflammation and bleeding can result. This further stimulates stomach acid production, worsening the condition.

The inflammatory changes that occur also inhibit the repair of damaged cells and reduce the production of protective mucus from the mucosal cells. This eventually leads to damage to deeper layers of the stomach's lining and causes stomach ulceration.

Common Causes of Stomach Ulceration in Dogs and Cats

Stomach ulcerations often happen due to increased production of gastric acid. This is usually caused by certain medications like corticosteroids and NSAIDs (Non-steroidal anti-inflammatory drugs) and certain antibiotics. Conditions like kidney and liver disease often cause decreased appetite, which increases the risk of hyperacidity and subsequent stomach ulceration in pets suffering from it.

Certain gastrointestinal parasites and infections also disrupt the protective barrier of the stomach lining and predispose it to damage and ulcer formation. Ingestion of foreign objects can mechanically damage and ulcerate the lining of the stomach, or worse, can cause complete perforation of the stomach wall.

Symptoms of Stomach Ulcers in Dogs and Cats

Stomach ulceration in dogs and cats causes several different clinical signs, most of which remain undetected until the condition becomes severe. Common symptoms associated with stomach ulcers are non-specific and can easily be confused with other conditions.

Initial signs include vomiting, abdominal pain, generalized weakness, and a decrease in appetite. As the condition becomes chronic, affected dogs and cats lose weight. When ulcers start bleeding, bloody vomit may be observed. Oftentimes, blood from bleeding ulcers is ingested and digested and causes a dark, tarry stool.

Severe cases of stomach ulcers and subsequent perforation lead to peritonitis and sepsis. Pets with perforated stomach ulcers often present with severe weakness, anemia, and pain. If left untreated, this can cause shock and eventual death of the pet.

How are stomach ulcers diagnosed in dogs and cats?

There are several ways your vet can diagnose stomach ulceration in a dog or cat showing symptoms suggestive of the disease. A physical exam can help determine the state of hydration of the pet and can detect the presence of abdominal pain.

Blood tests can help determine any systemic illness associated with the disease, such as anemia, secondary infection, and liver involvement. This also helps rule out other common causes of general signs of illness (vomiting, decrease in appetite, weakness, etc.).

Most cases would require imaging tests for a more accurate diagnosis. Radiographs (x-rays) can help rule out intestinal obstruction or intussusception, which can also cause continuous vomiting in dogs and cats. However, radiographs are of little help in confirming the presence of stomach ulcers.

Definitive diagnosis of stomach ulceration can be done through an endoscopic exam. This allows for real-time visualization of the stomach and intestinal lining to see ulcerations. Access to the lining of the stomach also allows biopsy sampling either by fine-needle aspiration or excision which can help further explore and determine any underlying cause of the stomach ulcers.

Treatment and Management of Stomach Ulcers in Pets

Treatment of stomach ulcers depends on the severity of the disease and the underlying cause. In most cases, dietary modification is needed in treating and managing the condition. H2-blockers like famotidine and proton-pump inhibitors like omeprazole reduce the production of gastric acid which helps reduce further injury to the stomach’s lining.

One thing pet owners need to be wary of when starting treatment for dogs or cats with stomach ulcers is rebound hyperacidity. Often, when long-term treatment with either an H2-blocker or a proton-pump inhibitor medicine is discontinued, gastric cells produce acids and enzymes at an increased rate which can worsen the condition. Gradual tapering of these medications is often needed once symptoms have been controlled.

Gastroprotectant medications like sucralfate coat the stomach’s lining and protect it from further injuries and damage. Cats and dogs diagnosed with stomach ulcers may need gastroprotectant treatment for an extended period to successfully manage the condition.

Antibiotics can be given at a prophylactic dose to prevent any secondary infection on the ulcers. However, care must be taken in using antibiotics, as some antibacterial medications can further stimulate gastric acid production.

Severe cases of stomach ulcers, those that have perforations and secondary peritonitis and sepsis, require hospitalization for intravenous fluid therapy and aggressive treatment. The prognosis for dogs and cats that have perforations are often poor.

Read more:

Common Causes of Stomach Upset (Gastritis) in Cats

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