Megaoesophagus in dogs

What are the causes of megaoesophagus?

This condition can occur for a variety of reasons and the most important ones are listed below. Causes can either be congenital (born with the condition) or acquired (develop later in life).

• Congenital megaoesophagus: This condition is usually diagnosed at around 8-12 weeks of age when puppies move into solid food. Half of dogs diagnosed with this disease will recover as they grow and reach adulthood. The condition is more common in certain breeds such as Great Danes, Labradors, Irish Setters and German Shepherd dogs
• Vascular ring anomaly: This is a congenital malformation where a band of tissue constricts the oesophagus and causes dilation. Surgical transection of the band of tissue is required
• Myasthenia gravis: This is the most common condition causing acquired megaoesophagus later in life. It is classed as an auto-immune condition in which the immune system acts against the muscles found in the oesophagus and causes them to become weak and unable to function well
• Idiopathic: This means that we cannot identify a cause for the problem. In large breed dogs megaesophagus can happen spontaneously
• Stricture: A stricture is a narrowing that forms in the oesophagus after some sort of damage, either from trauma, medication or reflux, which causes scarring. This can prevent food moving through and cause food to build up, causing dilation
• Oesophageal obstruction: A foreign body in the esophagus causing food to build up and dilation
• Addison’s disease / Hypoadrenocorticism: A complication of this syndrome due to the muscle weakness associated with hormonal changes. Usually good prognosis for recovery with treatment of the Addison’s Disease by supplementing with hormones

What are the symptoms of megaoesophagus ?

The main feature of this syndrome is regurgitation, where undigested food and saliva is produced from the mouth directly from the oesophagus. This is a passive process and food will fall out of the mouth, often undigested, in a long tube shape (the shape of the oesophagus) compared to vomiting which is an active process, associated with retching and often undigested food or bile. Regurgitation will often happen close to eating or drinking.

You may also notice difficulty swallowing and even if they do swallow the food doesn’t reach their stomach so they often seem hungry and lose weight. They may also have bad breath, lethargy and a cough.

How is megaoesophagus diagnosed?

Diagnosis is usually a combination of noticing the above symptoms, performing a clinical examination, and taking x-rays under anaesthetic to help visualise the size of the oesophagus.

How is megaoesphagus treated?

Treatment of this condition very much depends on the underlying cause and can be extremely difficult. Usually medications are required to help treat the inciting cause. Motility drugs can be used to help get the muscles moving. Surgery may be required for example for vascular ring anomaly or a foreign body.

Often dogs with megaoesophagus will need special diets and methods of feeding, for example feeding small balls of moist food from a height or in a special chair to aid food passage through the oesophagus into the stomach.

Are there long-term consequences of megaoesophagus?

Unfortunately, megaoesophagus has the potential to be fatal due to certain complications. The main one to worry about is aspiration pneumonia (bacterial infection of the lungs). Food and saliva may spill over from the dilated oesophagus into the windpipe, or be inhaled during regurgitation. Aspiration pneumonia will require treatment with antibiotics and in severe cases hospitalisation to monitor breathing.

Malnutrition is another common problem where the oesophagus is unable to transit enough food into the stomach to keep up with the dog’s energy needs.

Even without these complications, the chance of recovery depends upon the underlying cause and can vary from good to poor.

When should I contact my vet?

• If you notice your dog struggling to swallow

• If you notice your dog regurgitating food consistently

• If you notice your coughing or losing weight

Still have questions?

Book a video appointment to have a chat with one of our FirstVet vets for advice, treatment, and if necessary, referral to your local vet.