Gastrointestinal Ulcerations in Dogs

Overview of Canine Gastrointestinal Ulcerations

Gastrointestinal ulcerations are inflammatory lesions that extend into the deeper layers of the dog’s gastrointestinal tract, going beyond the mucosa (lining). They need to be differentiated from erosions, which are more superficial and involve only the mucosa.

Causes of Gastrointestinal Ulcerations

• Drugs
• Metabolic disease
• Stress
• Major medical illness
• Foreign objects
• Neoplasia (cancer)
• Gastroenteritis – gastrointestinal inflammation
• Lead poisoning
• Helicobacter pylori bacteria

What to Watch For

• Vomiting, with or without blood
• Melena, black, tarry stool that contains digested blood
• Abdominal pain
• Lack of appetite
• Pale gums
• Weakness
• Collapse
• Shock
• Sudden death

Diagnosis of Gastrointestinal Ulcerations in Dogs

Various tests are necessary to determine if an ulcer is present and the effects of the ulcer on the body. Tests may include:

• A complete blood cell count (CBC), biochemical profile, and urinalysis should be performed in all cases.
• Screening abdominal radiographs, although often within normal limits, may support the diagnosis of an ulcer secondary to a mass or foreign body.
• Abdominal ultrasound may detect associated masses or changes associated with ulceration, however the test generally does not identify gastrointestinal ulceration itself.
• A contrast upper GI study with barium may identify ulcers.
• Gastroduodenal endoscopy is the most definitive means of diagnosing gastrointestinal ulceration.

Treatment for Gastrointestinal Ulcerations in Dogs

Individuals with gastrointestinal ulceration may be treated as outpatients if there are minimal signs, no systemic effects, and especially if there is a known cause that can be removed immediately. Specific treatments may include:

• Restriction of all oral intake if there is active vomiting
• An easily digestible diet slowly reintroduced as frequent small feedings
• Avoidance of all gastric irritants like aspirin
• Acid blocking and stomach coating drugs
• In severe cases, hospitalization for intravenous fluid therapy and possibly blood transfusions

Home Care and Prevention

Administer all medication and dietary recommendations as directed by your veterinarian. If your dog becomes weak or pale, collapses, or vomits blood, seek veterinary attention at once.

Avoid gastric (stomach) irritants and stressful situations. If an underlying disorder has been diagnosed, treat your dog as directed, so as to prevent the onset of secondary ulcers.

Information In-depth for Gastrointestinal Ulcerations in Dogs

Gastrointestinal ulceration is the result of factors that alter, damage, or overwhelm the normal defense and normal repair mechanisms of the gastrointestinal mucosal (lining) barrier. There is no predilection for a particular age group or breed, and signs can be extremely variable from patient to patient. Some patients may have no clinical signs, while others may be in immediate need of intensive support and hospitalization, including blood transfusions.

There are many causes of gastrointestinal ulceration that range from drugs to tumors. It is important to realize that while some cases of ulceration are clear cut when reviewing the history, physical examination, and diagnostic findings, such as in the case of high dose aspirin administration in a dog with severe arthritis, others are more difficult to determine.

There are many diseases and disorders that cause similar clinical signs to patients with gastrointestinal ulceration, including:

• The ingestion of certain drugs and medications may either cause gastrointestinal ulceration or signs similar to individuals with ulceration, including vomiting and lack of appetite.
• Metabolic disorders like kidney failure, liver disease and hypoadrenocorticism are often associated with gastrointestinal ulceration.
• Stress, pain, fear or major medical illness to include shock, hypotension (low blood pressure), trauma, and major surgery can all be associated with gastrointestinal ulceration.
• Dietary indiscretion, or the ingestion of foreign bodies, is a common disorder seen in dogs. Vomiting, diarrhea, and gastric ulceration are commonly seen.
• Pancreatitis is an inflammation of the pancreas, and in certain cases, can be life-threatening. The most common clinical signs seen with pancreatitis are vomiting and lack of appetite. Pancreatitis can result in GI ulceration.
• Intestinal obstruction or blockage secondary to foreign bodies or tumors must be differentiated from and can cause GI ulceration. Mast cell tumors, cancer of the liver, and gastrin-secreting tumors of the pancreas should be considered.
• Infiltrative diseases of the gastrointestinal tract, which are microscopic diseases that penetrate and spread throughout, including inflammatory bowel disease and lymphosarcoma (cancer) must be ruled out.
• Hemorrhagic gastroenteritis is a syndrome of unknown cause seen in dogs. These animals often experience vomiting with or without blood and bloody diarrhea. Hemorrhagic gastroenteritis is most often seen in urban settings in small breed dogs.
• Clotting disorders, such as thrombocytopenia (decreased platelet count) or warfarin toxicity (rat poison), may have bloody diarrhea or vomiting.
• Neurologic disorders, especially of the vestibular center for balance and coordination will often experience vomiting.
• Certain toxins such as lead can cause severe gastrointestinal signs and ulceration.

Diagnosis In-depth of Gastrointestinal Ulcerations in Dogs

A diagnosis of gastrointestinal ulceration can be made more easily in some cases than in others, on the basis of history and clinical findings. Examples of these might include aspirin administration or known foreign body ingestion. A full diagnostic work-up is recommended, regardless of the cause.

• A complete blood count (CBC) will evaluate for the presence of infection, inflammation, and anemia, sometimes associated with gastrointestinal ulceration.
• A reticulocyte count should be performed on anemic animals. This will help determine if the type of anemia is consistent with gastrointestinal ulceration.
• A biochemical profile evaluates the kidney, liver, electrolytes, total protein, and blood sugar status. All of these parameters are important to establish in the dog with gastrointestinal ulceration, as it can be seen secondary to or associated with certain metabolic disorders.
• A urinalysis helps evaluate the kidneys and hydration status of the patient
• Multiple fecal examinations are important to rule out gastrointestinal parasites as a cause of vomiting, diarrhea, or other gastrointestinal signs.
• Abdominal radiographs (X-rays) evaluate the abdominal organs (kidneys, liver) and may help visualize the presence of a foreign body or tumor. They do not evaluate for the presence of an ulcer.

Your veterinarian may recommend additional tests to ensure optimal medical care. These are selected on a case-by-case basis.

• A coagulogram (clotting profile) may be recommended in cases where a clotting disorder is suspected. Patients with thrombocytopenia (decreased platelets) can present with bloody vomiting or diarrhea.
• An ACTH stimulation test may be recommended to rule out hypoadrenocorticism (Addison’s disease), which can cause gastrointestinal ulceration. It is a combination of 2 blood tests that measures adrenal function. It is safe and can usually be performed at your local veterinary hospital.
• Bile acids are paired blood tests obtained before and after a meal that evaluates liver function, as certain liver diseases can predispose to gastrointestinal ulceration. The test is very safe and can be performed at your local veterinary hospital.
• A blood lead level may be indicated in the patient with ulceration, where there has been known or possible lead exposure.
• A gastrin level should be run on any patient with multiple or recurrent ulcers or signs of ulceration. Elevated levels are usually seen in patients with gastrinomas (a tumor that secretes gastrin, increasing stomach acid production, causing ulceration.)
• An upper gastrointestinal (GI) barium (dye) series may be helpful in identifying ulcers. It may help diagnose foreign objects or tumors that are not apparent on radiographs, or confirm the location and extent of GI ulceration. A safe dye is given to the patient by mouth, and is then watched as it travels through the GI tract. It is a non-invasive test that can often be performed by your regular veterinarian, although in some cases may necessitate transfer to a specialty hospital.
• An abdominal ultrasound evaluates the abdominal organs and helps assess for the presence of tumors that may be associated with ulcers. Organs, lymph nodes, and masses can be sampled with a needle or biopsy instrument with the guidance of ultrasound. This procedure is relatively safe, however may necessitate a mild sedative. It is often recommended that a specialist perform the procedure.
• A bone marrow aspirate may be recommended in some patients with anemia, to determine if it is secondary to an ulcer, or to reveal evidence of a different disease process such as a mast cell tumor that can cause an ulcer. It is a relatively noninvasive test. It allows us to sample the bone marrow, which is responsible for producing red blood cells, white blood cells and platelets. With a local anesthetic, a small needle is introduced into the core of the bone, and a small amount of marrow is withdrawn and analyzed. This test may be performed by your local veterinarian, although in some cases, may be best to have performed in a specialty hospital.
• Gastroduodenoscopy may be of benefit in the patient with gastrointestinal ulceration. It may facilitate the removal of foreign bodies, help evaluate for ulcer disease, and sample tissue for the presence of inflammation or cancer, which may be the cause for the ulcer. Hospitalization is brief, and healing is generally quick and uneventful. It does, however, necessitate general anesthesia, and therefore is associated with minor risks. It is often necessary to refer the patient to a specialist, and is performed when other diagnostics are either inconclusive or support the diagnosis of a gastric foreign body or tumor, or a definitive diagnosis of ulceration is necessary.
• Lastly, an exploratory laparotomy should be performed as a diagnostic and sometimes therapeutic tool in any individual that has had an extensive diagnostic and sometimes therapeutic course, with little or no response. It is an invasive procedure, however is necessary in a handful of cases for a definitive diagnosis.

Therapy In-depth for Dogs with Gastrointestinal Ulcerations

Management of gastrointestinal ulcers center around treatment of the primary cause, inhibition of acid secretion, and, if necessary, control of hemorrhage. In cases of gastrointestinal ulceration, symptomatic therapy may be of benefit. These treatments may reduce severity of symptoms or provide relief for your dog. However, nonspecific therapy is not a substitute for definitive treatment of the underlying disease responsible for your dog’s condition.

• Withholding food and water for a period of time allows the GI tract to rest and is important in treating the patient with GI ulceration. Complete dietary restriction allows the lining of the GI tract to heal. Gradual reintroduction of small amounts of bland food should be instituted after the fast, and the dog maintained on a similar diet for weeks to months after the ulcer has been successfully treated.
• Drugs that decrease or inhibit acid production by the stomach such as Tagamet (cimetidine), Pepcid (famotidine), Zantac (ranitidine), Cytotec (misoprostol) and Prilosec (omeprazole) encourage and expedite the resolution of GI ulcers.
• Fluid and electrolyte therapy may be necessary in some patients with gastrointestinal ulceration, and is directed toward correcting dehydration, acid-base, and electrolyte abnormalities. Additionally, blood transfusions may be indicated in the severely anemic patients.
• Anti-emetic drugs stop vomiting and should be used with caution. Examples include Reglan (metoclopramide), Compazine (prochloperazine) or Thorazine (chlorpromazine). It is best to identify and treat the underlying cause of ulceration, however in selected cases their use may be recommended.
• Gastrointestinal protectants and adsorbents protect or sooth and coat an irritated gastrointestinal lining and bind noxious (harmful) agents. Examples include Carafate (sucralfate) and Pepto-Bismol (bismuth subsalicylate).
• Antibiotics are indicated in cases of bacterial infection, such as Heliobacter pylori.
• Endoscopy or surgery may be indicated to remove foreign objects or tumors causing gastritis, biopsy associated tissue with the ulcer, or physically remove an area of continual hemorrhage.

Follow-up Care for Dogs with Gastrointestinal Ulcerations

Optimal treatment for your dog requires a combination of home and professional veterinary care. Follow-up can be critical, especially if your dog does not rapidly improve. Administer all prescribed medication and diet as directed. Alert your veterinarian if you are experiencing problems treating your dog.

Discontinue and avoid any medication or substance that may be causing or exacerbating ulceration. Depending on the underlying cause of gastrointestinal ulceration, it may be necessary to return to your veterinarian for reevaluation of certain tests.