Gastrointestinal Ulcers in Dogs: What They Are and How To Help Your Pup

Gastroduodenal ulcer disease in dogs is a painful condition that develops when sores form in the lining of the stomach or upper small intestine. These ulcers can cause vomiting, loss of appetite, stomach pain, and gastrointestinal bleeding, and they may become life-threatening if left untreated.  

Early veterinary care is important, especially if your dog is vomiting blood, has black, tarry stools, or seems weak or lethargic. Many dogs recover well once the underlying cause is identified and treated. 

What Are Gastrointestinal Ulcers in Dogs?

Gastrointestinal ulcers are an erosion of one or more layers of the stomach or small intestines. Gastric, or stomach ulcers, are the most common, followed by ulcers in the first part of the small intestines, called the duodenum.   

During digestion, the stomach secretes harsh gastric acids and enzymes, which start breaking down food in the stomach to extract nutrients. To protect against these corrosive stomach juices, the stomach is lined with a mucosal barrier. If this barrier breaks down, the stomach lining will gradually erode, causing ulcers. 

Ulcers vary in severity. Erosions may wear through a few layers (non-perforating ulcers) or may create a hole through the stomach wall (perforating ulcers).  

Perforating ulcers are the most dangerous because holes in the gastrointestinal tract allow the stomach’s contents to spill into the abdominal cavity. Ulcers can affect the gastrointestinal and cardiovascular systems, which leads to sepsis. 

Call your veterinarian as soon as possible for an exam and diagnostic testing if you think your dog may have a gastrointestinal ulcer. 

Symptoms of Gastrointestinal Ulcers in Dogs

The most common sign of gastrointestinal ulcers is vomiting, often with blood. Depending on the ulcer’s severity, location, and frequency, other signs may include: 

• Weight loss 

• Melena (dark, tarry stools) 

• Diarrhea 

• Decreased appetite 

• Drooling 

• Dehydration 

• Abdominal pain (dogs may look at their abdomen, cry when touched, or go into a “praying” position) 

• Lethargy and weakness 

• Fever 

• Pale mucous membranes 

Causes of Gastrointestinal Ulcers in Dogs

There are broad categories of conditions or situations that cause gastrointestinal ulcers in dogs. Some are more common than others and include: 

• Drugs, such as NSAIDs (nonsteroidal anti-inflammatories, which include Rimadyl and Deramaxx) and steroids (like prednisone and dexamethasone). 

• Gastrointestinal diseases, including inflammatory bowel disease (IBD), ingested foreign material, and an increase in the production of gastric acid. 

• Infectious diseases, such as pythiosis (a waterborne infection) and helicobacter bacterial infections. 

• Metabolic diseases, including liver, kidneys, and adrenal glands (Addison’s disease). 

• Heavy metal poisoning, including arsenic, zinc, thallium, iron, and lead. 

• Cancers of the gastrointestinal tract, such as carcinoma, lymphoma, leiomyoma, and GI stromal tumor. 

Stress can also lead to ulcers. Severe shock and low blood pressure (usually due to trauma or surgery), heatstroke sepsis, thermal burns, and strenuous exercise in extreme temperatures (cold or hot) are some examples of stressors. 

Sled dogs, and other canine athletes, are prone to develop stomach ulcers. 

How Veterinarians Diagnose Gastrointestinal Ulcers in Dogs

A biopsy is required to diagnose a gastrointestinal ulcer in dogs. Biopsy samples are especially useful to determine the underlying reason for the ulcer, most notably cancer or infections. 

Veterinarians may recommend many tests before getting to a biopsy. A dog’s history of vomiting, especially with blood, may give veterinarians a strong suspicion of an ulcer, especially a dog who has a history of being prescribed ulcer-causing drugs (NSAIDs or steroids).  

Tests may include: 

• Blood work 

• Fecal testing 

• X-rays 

• Ultrasounds 

Treatment of Gastrointestinal Ulcers in Dogs

Removal of any underlying cause (drugs, toxicities, cancer) is the priority in treating dogs with gastrointestinal ulcers.  

Dogs with stomach ulcers may require hospitalization and supportive care, depending on the severity. 

Clinically sick dogs and those with perforated ulcers require intensive nursing care. These animals may require: 

• Blood transfusions 

• Intravenous (IV) fluid support 

• Emergency surgery 

• Antibiotics and pain medications 

Partial-thickness, nonperforating ulcers may be treated on an outpatient basis. These dogs will require a bland diet and gastroprotectant medications. 

Common GI medications include: 

• Sucralfate protects the mucosa by coating the ulcer. It can also stimulate ulcer healing. 

• H2 receptor antagonists block receptors in the stomach to decrease gastric acid secretion. The most well-known H2 receptor antagonist is Pepcid (famotidine). 

• Proton pump inhibitors are generally regarded as superior to H2 receptor antagonists to prevent ulcerations. Omeprazole, pantoprazole, lansoprazole, and esomeprazole are all options in this drug family. 

• Prostaglandin E analogs, like misoprostol (Cytotec) works by increasing mucosal protection by decreasing gastric acid secretion. Some veterinarians will use this drug to prevent ulcers in animals with chronic NSAID therapy. 

Dogs may require a long-term diet change.  

However, if the underlying cause is removed, they may return to normal life. Common diet recommendations include: 

• Purina EN 

• Royal Canin GI 

• Hill’s i/d 

Surgical therapy may also be considered if an ulcer has gone through the stomach lining, or if cancer is present. 

Recovery and Management of Gastrointestinal Ulcers in Dogs

The prognosis for dogs with gastrointestinal ulcers is typically good and based on underlying causes and response to treatment.  

Perforated ulcers are more serious, and the prognosis is guarded. Less complicated forms of ulcers should show signs of improvement within five to seven days. 

Depending on the cause, some dogs may be at risk for future ulcerations. These dogs may be placed on specialized gastrointestinal diets and may remain on ulcer-preventive drugs, such as omeprazole. 

Dogs on chronic NSAID therapy may benefit from receiving their NSAID with food, in addition to preventive GI medications.