Gastroesophageal reflux
Gastroesophageal reflux disease (GERD) is one of the most commonly diagnosed gastrointestinal disorders in humans. In contrast, GERD has been considered an uncommon disorder in dogs and cats, but is likely more common than previously thought.13,14,18,23 GER is caused by relaxation of the lower esophageal sphincter leading to reflux of gastric material into the esophagus.
Varying degrees of esophagitis may result. Refluxed material may contain acid, pepsin, or even trypsin and bile acids, which may damage the esophageal mucosa. The frequency and content of the reflux determine the severity of the condition.24 Gastric acid alone may cause mild esophagitis, whereas acid combined with pepsin, trypsin, and /or bile acids may lead to severe esophagitis, and the more frequent the contact, the more likely esophagitis is to develop.24 The most common cause of GER is general anesthesia, especially in those animals undergoing intra-abdominal procedures.14,18,23,25 Other disorders such as chronic vomiting, hiatal hernia, and esophageal foreign body may also predispose an animal to GER; but GER may also be idiopathic.13,18,23Clinical signs of GER may mimic those of esophagitis. Animals with mild GER may regurgitate small amounts of material and may be seen to eructate followed by swallowing movements, or may be completely asymptomatic. Regurgitation, odynophagia, multiple attempts at swallowing with extension of the head and neck, and ptyalism may all be seen with moderate to severe disease.13,14 The owner should be carefully asked whether the animal has recently undergone general anesthesia. The physical examination is often unremarkable and results of the minimum database, including thoracic radiographs, are often within normal limits. A definitive diagnosis is made with a combination of contrast videofluoroscopy and endoscopy. Contrast videofluoroscopy can demonstrate reflux of gastric contents into the distal esophagus, decreased esophageal motility, and potentially may reveal evidence for an underlying condition, such as a hiatal hernia.13,14 Endoscopy may be normal, but if esophagitis is present, varying degrees of mucosal hyperemia, irregularity, and /or erosion or ulceration may be seen.13,14 Various agents used to premedicate and induce animals for anesthesia may decrease lower esophageal sphincter tone, which must be taken into consideration when an open lower esophageal sphincter is seen during endoscopy.26
Therapy for GER is similar to that for esophagitis.
Treatment of esophageal damage is important, as is promoting an increase in lower esophageal sphincter tone and gastric emptying. Therefore, oral sucralfate suspension is used if esophageal erosions or ulcerations are seen, or when the clinician aims to prevent such changes.20 Additionally, an H2-receptor antagonist or a proton pump inhibitor along with a prokinetic agent should be administered.13,14,22,21 In the past, it has been recommended to feed a low fat or fat-restricted diet, as dietary fat may delay gastric emptying and decrease lower esophageal sphincter tone;17 however, recent evidence in humans has shown that this may not be the case in all patients.27,28 A fat- restricted diet may be utilized initially, but if the patient does not maintain an adequate body condition, a diet with a moderate amount of fat should be chosen. Any underlying conditions that can be identified should also be corrected. However, the surgical correction of primary GER has not been recommended in veterinary patients to date as has been the case in some human patients.293.3.4