Gastrinoma is a malignant tumor of the pancreas that secretes a hormone called gastrin that stimulates acid secretion in the stomach and in turn causes gastrointestinal ulceration. In human medicine gastrinomas are referred to as the Zollinger-Ellison syndrome.

There is no specific known cause or risk factor that is responsible for gastrinomas. This cancer is not very common in veterinary medicine and is seen more commonly in dogs than cats. Middle-aged to older dogs are most commonly affected. There does not appear to be a gender or breed predisposition.

What to Watch For

Although some patients may have no clinical signs, some may have life threatening manifestations.

Vomiting (with or without blood)

Diarrhea

Melena, which is black, tarry stool that contains digested blood

Abdominal pain

Anorexia

Weight loss

Depression

Pale mucus membranes

Weakness

Collapse

Shock

Sudden death

Diagnosis

A complete blood cell count (CBC), biochemical profile and urinalysis should be performed in all cases.

Screening abdominal X-rays, although often within normal limits, may be of benefit in ruling out other disorders.

Abdominal ultrasound may identify a pancreatic mass, but it generally does not identify gastrointestinal ulceration itself.

A contrast upper gastrointestinal study may identify ulcers.

Gastroduodenal endoscopy is helpful in diagnosing gastrointestinal ulceration, although it does not always identify an underlying cause.

Gastrin levels may help to support a diagnosis of a gastrinoma.

Laparotomy and biopsy of the pancreatic mass is the only definitive way of documenting a gastrinoma.

Treatment

Treatment of gastrinoma patients should be directed at surgical excision of the tumor and control of excess gastric acid secretion.

In severe cases, hospitalization is warranted for intravenous fluid therapy and/or blood transfusions

If possible, treatment of choice is surgical removal of the tumor.

Large bleeding ulcers may also need to be removed surgically.

Individuals with gastrointestinal ulceration may be treated as outpatients if there are minimal signs and/or no systemic effects.

Food and water should be restricted if there is active vomiting, and an easily digestible diet with frequent small feedings should be reintroduced gradually.

Acid-blocking and stomach-coating drugs may be recommended.

Home Care and Prevention

Long term prognosis is poor because of the likelihood of malignancy with these types of tumors. Administer all medication and dietary recommendations as directed by your veterinarian. If your pet becomes weak, pale, or if he collapses or vomits blood, seek veterinary attention at once.

There is no preventative care for gastrinomas.