Report supports rational administration of gastroprotectants to dogs and cats

Increasing evidence says these drugs are not benign
Published on May 29, 2019
Esophagoscopy image
An image obtained during an esophagoscopy procedure shows severe esophagitis and multifocal esophageal erosions in a dog secondary to gastroesophageal reflux associated with an elective dental cleaning. According to a consensus statement published in the Journal of Veterinary Internal Medicine on gastroprotectants, "Acid-suppressing agents may be beneficial for prevention of esophagitis secondary to GER, particularly in animals when it is associated with an anesthetic procedure." (Courtesy of Dr. Stanley Marks)

Concerns have been raised that, as in human patients, acid suppressants are being overprescribed and misused in canine and feline patients. Along with worries that gastric acid suppressants can cause changes in drug absorption and malabsorption of certain nutrients, there is some evidence that they can result in an increased risk of enteric infections, such as with Salmonella and Campylobacter, because of acid suppression removing an important physiologic barrier to these organisms.

In response, a panel of five veterinary academicians with clinical and research expertise in the area of gastric protectants published a consensus statement titled "Support for rational administration of gastrointestinal protectants to dogs and cats."

One of the study's authors, Dr. Stanley L. Marks, chief of the Small Animal Medicine Service at the University of California-Davis School of Veterinary Medicine, told JAVMA News, "The use, or misuse rather, and injudicious administration of acid suppressants have been rampant in both the human and veterinary professions."

He said there is increasing evidence that these drugs are not benign. Acid suppressants can adversely affect the absorption of other agents that require an acid milieu for oral absorption—such as antifungal drugs of the azole class, mycophenolate, and orally administered iron—and long-term administration can have adverse effects. In addition, co-administration of sucralfate with orally administered ciprofloxacin, theophylline, tetracycline, doxycycline, phenytoin, and digoxin substantially decreases the bioavailability of these drugs.

Endoscopic view in the antrum of a dog
An endoscopic view shows a gastric ulcer in the antrum of a dog that had been treated with nonsteroidal anti-inflammatory drugs. According to the consensus statement, proton pump inhibitors should be considered the standard of care for medical treatment of gastroduodenal ulceration in dogs and cats. (Courtesy of Dr. Michael Willard)

"Unfortunately, there is a dearth of sound research in the veterinary profession evaluating the utility of gastric protectants in clinically affected dogs and cats with spontaneous disease, and most of the studies evaluating the efficacy of these drugs have been performed in healthy animals," Dr. Marks said."

He said healing of gastroduodenal ulcers and erosive esophagitis is directly related to the extent and duration of gastric acid suppression over a 24-hour period, and specific guidelines have been published in the human literature for optimizing the healing of esophagitis and gastroduodenal ulcers. Similar guidelines have not been established for the healing of these lesions in dogs and cats to date.

Dr. Marks hopes the consensus statement "will facilitate improved stewardship in the use of gastric protectants in our profession and will also help veterinarians recognize the optimal methods for administering these drugs to maximize their benefit while minimizing adverse effects." He continued, "We clearly need to do a better job utilizing gastric protectants more judiciously in our profession."

Furthermore, according to the abstract, "This report challenges the dogma and clinical practice of administering GI protectants for the routine management of gastritis, pancreatitis, hepatic disease, and renal disease in dogs and cats lacking additional risk factors for ulceration or concerns for GI bleeding."

The consensus statement offers information on gastroprotectants in humans, dogs, and cats regarding mechanism of action, biological targets, efficacy, adverse effects, and drug interactions. The statement then covers the evidence to support clinical use of gastroprotectants in dogs and cats with various conditions.

Lateral radiograph
A lateral radiograph of the thorax of a dog shows two Bravo pH monitoring capsules for measuring intragastric and esophageal pH. One capsule is attached to the mucosa of the gastric fundus; the other is attached to the esophageal mucosa proximal to the lower esophageal sphincter. (Courtesy of Dr. Peter Kook)

According to the abstract, "This report offers a consensus opinion on the rational administration of GI protectants to dogs and cats, with an emphasis on proton pump inhibitors (PPIs), histamine type-2 receptor antagonists (H2RAs), misoprostol, and sucralfate." These drugs have transformed management of reflux esophagitis and gastroduodenal ulceration in human and veterinary patients.

The ability to accurately and noninvasively measure intragastric pH with catheterless radiotelemetric pH monitoring devices, such as the Bravo pH monitoring system, has advanced the understanding of the effects of acid suppressants and dosing protocols on intragastric pH in animals in recent years, according to the report, and should facilitate future research to more precisely identify the efficacy of these drugs in dogs and cats with spontaneous disease.

Dr. Marks hopes that, in the next five or six years, new research data generated in clinically affected animals and ongoing studies assessing dosing protocols will allow for more specific guidelines by condition.

The study's other authors are Drs. Peter H. Kook at the University of Zurich, Mark G. Papich at North Carolina State University, and M. Katie Tolbert and Michael D. Willard at Texas A&M University. The Board of Regents of the American College of Veterinary Internal Medicine approved the statement, which was published Oct. 31 in the Journal of Veterinary Internal Medicine.