888. Megaesophagus in the older dog - treatment

Regurgitation is the presenting sign. Mistaken for "vomiting" which is a projectile action.

D/D for regurgitation
1. Esophageal obstruction. Vascular ring anomaly, stricture, foreign body, neoplasia (spirocerca lupi).
2. Motility disorders. Megaoesophagus - congential
- acquired --- primary (idiopathic)
--- secondary
Dysautonomia
3. Inflammatory. Esophagitis (secondary to protracted vomiting), caustic irriation. Hiatal hernia. Gastro-esophageal reflux.
4. Others. Diverticula, Broncho-esophageal fistula.
5. Idiopathic.


DIAGNOSIS
1. History - Other clinical signs, young or older breed, large breed
2. Physical exam - incl full neurological exam, thorough thoracic auscultation (aspsiration pneumonia, caudal lobes on X-ray)>

THORACIC X-RAY. Needs 3 views. 2 lateral + V/D. Look for aspiration pneumonia, cranial mediastinal mass, air in esophagus (one lateral without sedation as drugs can cause air in esophagus).

Contrast studies. Liquid barium using plain X-rays, evidence of strictures, vascular ring anomaly (puppies).

Food and barium dynamic studies (fluoroscopy) to assess motility of esophagus.

Other investigations to identify underlying problems.

TREATMENT depends on causes

Distemper, autonomic drugs, toxicity (lead, thallium, anti-cholilnesterase), esophigitis, systemic lupus erythematosus, hypoadrenocorticisum, thyoma, myasthenia gravis (focal, most common cause, auto-antibodies produced againt Ach receptors), polymyositis.

1. Vertical feeding - Feed from a height. Bailey's chair. 1 hour upright feeding.
2. Bethanechol or cisapride for myasthenia gravis

CASE STUDY
Use of barium meal showed esophagus enlarged in two areas, convincing the owner of the diagnosis. Plain X-ray not so clear in showing megaesophagus.
2. Dietary - canned food, meat balls. No dry food.
3. If myasthenia gravis, require anit-cholinesterase drugs and immune suppression.
bethanechol or cisapride