CONDITION
Gastric Ulceration
Gastric ulceration describes erosions or breaks in the protective lining of the stomach, exposing the tissue beneath to digestive acid. These lesions can range from superficial damage to deeper wounds that may bleed or, in some cases, perforate the stomach wall. Owners often arrive at this page because their dog or cat has been vomiting, sometimes with fresh blood or dark, digested blood that resembles coffee grounds. Other times the concern is less specific—reduced appetite, signs of nausea, weight loss, or dark tarry stools that suggest bleeding higher in the digestive tract. In some animals, ulceration is discovered incidentally during investigation of another condition, without obvious signs at home. This page explores the patterns that may raise suspicion, the mechanisms that allow ulcers to form, the ways they are identified through examination and imaging, and the range of approaches used to support healing and manage underlying causes.
Why this matters now
Gastric ulceration can develop at any age, though certain patterns emerge more frequently in middle-aged and older animals. Dogs receiving long-term non-steroidal anti-inflammatory drugs, those with severe systemic illness, or animals experiencing significant stress or pain tend to be at higher risk. Some breeds, particularly those prone to mast cell tumours or other conditions that increase gastric acid production, may be more susceptible. Cats appear to develop gastric ulceration less commonly than dogs, though it can occur secondary to kidney disease, liver disease, or certain medications.
The timeline varies considerably between individuals. Some ulcers develop rapidly over days in response to acute stressors or medication exposure, while others form gradually over weeks or months alongside chronic illness. Superficial erosions may heal spontaneously if the underlying trigger resolves, but deeper ulcers often persist or worsen without intervention. Bleeding may be intermittent or continuous, and in some cases perforation can occur, though this remains uncommon.
Signals & patterns
Early signals
Reduced interest in food
An animal may approach the bowl, sniff, and turn away, or eat smaller portions than usual. This often reflects nausea or discomfort associated with an empty or recently filled stomach.
Lip licking or swallowing
Repeated licking of the lips or frequent swallowing when no food is present can indicate nausea. The behaviour often appears subtle and may be mistaken for normal grooming.
Restlessness or positional changes
Some animals become reluctant to settle, shifting position frequently or moving between resting spots. This may reflect abdominal discomfort that worsens or improves with posture.
Intermittent vomiting
Vomiting may occur occasionally, particularly after meals or in the early morning when the stomach is empty. The vomited material may be bile-stained or contain undigested food.
Later signals
Vomiting with blood
Fresh red blood or dark, granular material resembling coffee grounds may appear in vomit, indicating bleeding from the stomach lining. The colour depends on how long blood has been exposed to stomach acid.
Dark, tarry stools
Melaena—black, sticky, foul-smelling faeces—results from digested blood passing through the intestines. This suggests significant or sustained bleeding from the upper digestive tract.
Pale gums or weakness
Chronic or acute blood loss can lead to anaemia, resulting in pale mucous membranes, lethargy, or reduced tolerance for activity. These signs often develop gradually unless bleeding is rapid.
Weight loss or muscle wasting
Persistent nausea, reduced food intake, and ongoing inflammation can lead to progressive weight loss. Muscle condition may decline even if the animal continues to eat small amounts.
Click to read about the biological mechanisms
How this is usually investigated
Investigation typically begins with a detailed history of symptoms, recent medication use, and any concurrent illness, followed by physical examination to assess hydration, abdominal discomfort, and signs of blood loss. The pattern of vomiting, appearance of any blood, and presence of dark stools help shape the initial picture. Further testing is guided by the clinical findings and may include blood work, imaging, and in some cases direct visualisation of the stomach lining.
Physical examination
Blood biochemistry and haematology
Abdominal radiography
Abdominal ultrasonography
Gastroscopy
Options & trade-offs
Management typically involves a combination of approaches tailored to the individual animal, the severity of ulceration, and any underlying triggers. Some animals respond to medication and dietary adjustment alone, while others require more intensive support or treatment of concurrent disease. The approach that suits one household or animal may not align well with another's circumstances or tolerance.
Gastric acid suppression
Medications that reduce stomach acid production, such as proton pump inhibitors or histamine receptor antagonists, allow the stomach lining time to heal by reducing ongoing acid exposure. These drugs are often given once or twice daily, and the duration of treatment varies depending on ulcer severity and response. Some animals require long-term therapy if the underlying cause persists or cannot be fully addressed.
Trade-offs: Acid suppression does not address the root cause of ulceration and may be less effective if protective mechanisms remain impaired. Prolonged use can alter gastric pH and potentially affect nutrient absorption or microbial balance, though clinical consequences in dogs and cats remain unclear.
Mucosal protectants
Compounds such as sucralfate coat ulcerated tissue and create a physical barrier against acid and enzymes, promoting local healing. These agents are typically given multiple times daily on an empty stomach to maximise contact with the damaged lining. They are often used alongside acid suppression rather than as sole therapy.
Trade-offs: Frequent dosing can be challenging in some households, and the protective coating is temporary, requiring consistent administration. Efficacy may be limited in animals with very deep ulcers or ongoing acid hypersecretion.
Dietary modification
Feeding small, frequent meals of easily digestible food can reduce the mechanical and chemical demands on the stomach lining. Bland diets low in fat and fibre are often used during the acute phase, with gradual reintroduction of the usual diet as healing progresses. Some animals benefit from avoiding foods that increase gastric acidity or delay gastric emptying.
Trade-offs: Dietary changes alone are unlikely to resolve moderate to severe ulceration without concurrent medication. Palatability can be an issue in animals with reduced appetite, and strict adherence may be difficult in multi-pet households or for animals accustomed to varied diets.
Withdrawal or adjustment of contributing medications
If gastric ulceration has developed in association with non-steroidal anti-inflammatory drugs or corticosteroids, cessation or dose reduction may allow healing, provided the underlying pain or inflammation can be managed through alternative means. In some cases, a switch to a different class of medication or the addition of gastroprotective drugs permits continuation of necessary therapy.
Trade-offs: Stopping pain relief can diminish quality of life in animals with musculoskeletal disease or chronic pain, and alternative analgesics may carry their own side effects or prove less effective. The decision involves weighing the risks of ongoing medication against the consequences of untreated pain.
Treatment of underlying disease
Addressing concurrent conditions such as mast cell tumours, kidney disease, liver disease, or systemic infection can remove the trigger for ulcer formation and improve the stomach's capacity to heal. This may involve surgery, chemotherapy, antimicrobials, or supportive care depending on the diagnosis. Resolution of the primary condition often leads to resolution of gastric ulceration over time.
Trade-offs: Underlying disease may not be fully curable, and treatment can be prolonged, expensive, or carry its own risks. In some cases, ulceration persists despite management of the primary condition, requiring ongoing gastroprotective therapy.
Common misconceptions
"Gastric ulcers only occur in dogs taking anti-inflammatory drugs."
While non-steroidal anti-inflammatory drugs are a well-recognised risk factor, gastric ulceration can develop in animals that have never received these medications. Severe illness, stress, kidney or liver disease, and certain tumours can all trigger ulcer formation independently. Some animals develop ulcers without an obvious precipitating cause.
"If a dog vomits blood, the ulcer has perforated."
Vomiting blood indicates that a vessel within the stomach lining has been eroded by the ulcer, but perforation—where the ulcer penetrates the full thickness of the stomach wall—is a separate and less common complication. Most animals that vomit blood have bleeding ulcers that remain contained within the stomach. Perforation typically produces signs of abdominal pain, shock, and free fluid or gas in the abdomen.
"Once an ulcer has healed, it will not recur."
Healing reflects repair of the damaged tissue, but if the underlying cause persists or recurs—such as ongoing medication use, chronic disease, or repeated stress—new ulcers can form. Some animals experience recurrent ulceration and may require long-term management to maintain the integrity of the stomach lining.
Related conditions
Acute Kidney Injury
Acute kidney injury can arise as a consequence of gastric ulceration when substantial bleeding leads to reduced blood flow to the kidneys, or when systemic illness associated with ulceration strains renal function. Conversely, non-steroidal anti-inflammatory drugs—a recognised cause of gastric ulceration—can also damage the kidneys directly, meaning the two conditions may share a common trigger.
Liver Disease in Dogs
Liver disease can contribute to gastric ulceration through several pathways: reduced production of clotting proteins may prolong bleeding from even minor erosions, and the accumulation of toxins that a failing liver cannot clear can irritate the stomach lining. Both conditions may also share underlying causes, such as certain medications or systemic illness.
Pancreatitis in Dogs
Pancreatitis and gastric ulceration can occur together, particularly in dogs with severe or recurrent pancreatic inflammation; the inflammatory mediators released during pancreatitis may disrupt the protective barrier of the stomach, and both conditions often present with vomiting and reduced appetite. Pain from either source can complicate the clinical picture, making it difficult to attribute signs to one condition alone.
Cushings Disease in Dogs
Cushing's disease is associated with an increased risk of gastric ulceration, as prolonged exposure to elevated cortisol reduces the stomach's ability to maintain its protective mucus layer and may increase acid secretion. Dogs with Cushing's who develop ulcers may show subtle or overlapping signs, since both conditions can affect appetite and energy.
Gastroenteritis in Dogs
Gastroenteritis in dogs shares several presenting signs with gastric ulceration—vomiting, reduced appetite, and abdominal discomfort—which can make differentiation challenging in the early stages. While gastroenteritis typically involves more diffuse inflammation of the stomach and intestines, localised ulceration may be present in some cases, particularly when the inflammation is severe or prolonged.
Gastric ulceration often exists alongside broader patterns of digestive disturbance or systemic illness, and understanding how these layers interact can clarify the larger picture. The pillar on Metabolic Health explores how organ function, medication effects, and inflammation influence one another. For animals with ongoing nausea or appetite changes, the pages on vomiting patterns and weight loss may offer useful context for future conversations.
Last reviewed: 1 July 2026 · Dr Alastair Greenway MRCVS