Acquired megaoesophagus in dogs: causes and management
5-year-old Golden Retriever with regurgitation for three weeks. Thoracic radiographs confirm generalised megaoesophagus without pneumonia. Neurological examination shows no obvious weakness at rest.
What is the most appropriate initial plan?
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A. Measure acetylcholine receptor antibodies, rule out hypoadrenocorticism and feed in an upright position with whatever food consistency is best tolerated
Correct. Acquired myasthenia gravis is the most common identifiable cause and may be oesophageal only (focal), without weakness. Addison's disease is also treatable. Upright feeding (e.g. a Bailey chair) uses gravity and reduces aspiration.
B. High-dose metoclopramide, which restores oesophageal peristalsis
In dogs the oesophagus is striated muscle and metoclopramide does not improve its motility; it may even increase sphincter tone and worsen emptying.
C. Surgical oesophagoplasty to reduce oesophageal calibre
No surgical technique corrects generalised megaoesophagus. Surgery only makes sense for obstructive causes, such as a vascular ring.
D. Continuous prophylactic antibiotics to prevent aspiration pneumonia
Antibiotics are used when pneumonia is present, not as continuous prophylaxis, which only selects for resistance. Prevention is upright feeding.
lightbulb Key takeaway
Always look for treatable causes: myasthenia gravis (anti-AChR antibodies), hypoadrenocorticism, severe oesophagitis and, in some cases, hypothyroidism or polymyositis. Keep the dog upright for 10–15 minutes after eating. Aspiration pneumonia is the main cause of death.
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Updated: October 31, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.