- Esophagitis is inflammation of the esophageal mucosa.
- Prevalence in dogs and cats is unknown, but underdiagnosis is likely, as clinical signs can be subtle or frequently confused with vomiting.
- Pay particular attention to pets that start vomiting within hours to days of anesthesia, as anesthesia-associated gastroesophageal reflux (GER) is a common cause of esophagitis.
- Geographic factors are unlikely to influence most cases unless Spirocerca lupi is endemic.
- Any dog or cat may develop esophagitis once esophageal mucosal injury occurs.
- Certain canine breeds (eg, brachycephalic breeds, shar-peis) are at increased risk for hiatal hernia and abnormal lower esophageal sphincter (LES) function, placing them at greater risk for GER-induced esophagitis.
- Female dogs are at increased risk for esophageal strictures (sequela of esophagitis) compared with males, although the reason is unclear.
- Chemical or mechanical injury to esophageal mucosa:
- Most frequently results from GER at time of general anesthesia, although other causes of GER exist (eg, frequent or persistent vomiting, abnormal LES function, brachycephalic airway obstruction syndrome [BAOS]).
- Can also result from caustic substance ingestion (eg, strong alkalis in cleaning products), retention of certain medications within the esophageal lumen (pill esophagitis, which is well reported in cats1), and radiation-induced cellular injury.
- Ingestion of abrasive or sharp foreign material.
- In dogs, esophageal inflammation associated with infection (eg, Pythium insidiosum, S lupi) and allergy can cause pyogranulomatous and eosinophilic esophagitis, respectively.2
- Retention of hair balls (trichobezoars) within the esophagus has been associated with esophageal strictures in cats.
- Presumably plays a role in development of esophagitis.
- GER is associated with anesthesia, frequent or persistent vomiting, and abnormal LES function (eg, hiatal hernia, BAOS).
- Foreign body ingestion/injury (eg, bones, plastic, trichobezoars [cats]).
- Certain oral medications (eg, doxycycline, clindamycin, bisphosphonates).
- Caustic substance ingestion (eg, strong alkali or acidic cleaning products).
- Radiation therapy in proximity of the esophagus.
- For GER-induced chemical injury to esophageal mucosa, both the character of reflux (pH, bile acids, pepsin, trypsin content) and length of contact time are important determinants of injury.
- Because most pets with esophagitis present for vomiting, always attempt to differentiate vomiting from regurgitation (Table). Unlike vomiting, regurgitation is a passive process that typically occurs without warning.
- Dysphagia, gagging, ptyalism, odynophagia (painful swallowing), exaggerated swallowing or head and neck movements, lip licking, weight loss, inappetence, and coughing may be present.
- Owners often underappreciate these signs.
- Cats may present with signs of apparent respiratory distress without evidence of aspiration pneumonia.
- Observing the pet while it eats is an important initial diagnostic investigation when history fails to confirm regurgitation or vomiting.
- General signs of malaise (inappetence, lethargy), ptyalism, and dysphagia may indicate esophageal pain.
Table. Differentiating Regurgitation from Vomiting