Megaesophagus

Megaesophagus



Basic Information image



Definition


Chronic dilation (ectasia) and atony of the body of the esophagus



Synonym(s)


Esophageal ectasia



Epidemiology



Species, Age, Sex




• Congenital megaesophagus is seen in foals and young adult horses.


• Acquired megaesophagus may occur at any age.



Associated Conditions and Disorders




• Gastroduodenal ulceration


• Botulism


• Equine grass sickness


• Fourth branchial arch defect



Clinical Presentation



History, Chief Complaint




• Clinical signs of esophageal dysphagia:


image Hypersalivation

image Regurgitation

image Weight loss

image Coughing associated with eating

image Nasal discharge containing food material

• Onset of signs usually insidious



Physical Exam Findings


The findings of physical examination confirm the presenting signs, including dysphagia, hypersalivation, and nasal discharge containing food material. Distension of the cervical esophagus may be visible or palpable. The horse may be noted to eructate frequently.



Etiology and Pathophysiology




• Congenital megaesophagus may be inherited in a similar fashion to congenital megaesophagus in dogs. Some horses affected by fourth branchial arch defect may also have megaesophagus and achalasia of the upper esophageal sphincter.


• Acquired megaesophagus may be secondary to chronic or recurrent esophageal obstruction, esophageal obstruction by tumors and other masses, vascular ring anomalies, neurologic diseases (eg, equine protozoal myeloencephalitis, idiopathic vagal neuropathy), pleuropneumonia (and associated vagal neuropathy), equine grass sickness, botulism, or myasthenia gravis.


• Temporary iatrogenic megaesophagus may occur after sedation with α2-adrenergic agonists, such as detomidine.

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Jul 24, 2016 | Posted by in SMALL ANIMAL | Comments Off on Megaesophagus

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