How Do You Treat Megaesophagus In Cats? The Effects of an Enlarged Esophagus

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Has your cat been regurgitating often and seemingly a bit thinner than normal? There is a possibility that your cat may have megaesophagus, a congenital condition where your cat's esophagus is not contracting and allowing your cat to swallow food normally. Learn more here.

Megaesophagus is a condition characterized by an enlarged and malfunctioning esophagus, which is the tube that carries food and liquids from the mouth to the stomach. When the esophagus is functioning properly, a reflex causes contractions that propel food and water into the stomach. Another reflex prevents breathing during swallowing so that a cat will not inhale food or liquids into the lungs.

In cases of megaesophagus, a disease, physical blockage, or congenital defect will cause these reflexes to fail, and the esophagus will lose muscle tone and remain enlarged rather than contracting. Because foods and liquids cannot make their way into the stomach, a cat may regurgitate and begin to lose weight. In addition, foods or liquids that are inhaled into the lungs can cause aspiration pneumonia, which can be fatal if not treated promptly.

Here we will review the causes, symptoms, and treatments of megaesophagus in cats so that you will know what to look out for and when to seek help.

Causes of Megaesophagus in Cats

Megaesophagus in cats is either congenital (present since birth) or acquired.

In congenital cases, the cause may be unknown, or it may be the result of a genetic developmental abnormality that causes inadequate nerve function. Siamese cats seem to be at particular risk for congenital megaesophagus.

In acquired cases, the condition is either primary or secondary. In primary cases, the cause is commonly idiopathic, or not traceable. In secondary cases, megaesophagus is the result of another medical issue, such as a foreign object blockage, esophageal tumor, heavy metal poisoning, parasitic infection, or a neuromuscular disease. Neuromuscular diseases are those in which muscle function is impaired because muscles are not receiving signals from the nervous system. In the case of megaesophagus, the impairment would be seen in the esophageal muscle that is failing to contract.

Symptoms of Megaesophagus in Cats

The most common symptoms of megaesophagus in cats include:

  • Regurgitation (this is different than vomiting; vomiting is when contents are actively pushed out of the stomach; regurgitation is when contents fall out of the mouth or throat)

  • Weight loss

  • Symptoms associated with aspiration pneumonia: coughing, nasal discharge, difficulty breathing, difficulty swallowing, lethargy, weakness, fever, blue-tinted skin.

Treatment for Megaesophagus in Cats

To diagnose megaesophagus, your veterinarian will perform a physical examination on your cat, ask you about their symptoms, and use certain tests. X-rays and ultrasounds are commonly used because they can reveal an enlarged esophagus, material in the esophagus, and abnormalities associated with aspiration pneumonia.

There is no cure for megaesophagus. In some cases, surgery may be attempted to correct a congenital defect, but it can be risky.

In most cases -- whether congenital or acquired -- treatment will be purely supportive, and the goal of treatment is to improve swallowing and digestion.

If your cat is suffering from aspiration pneumonia, they may require immediate hospitalization and antibiotics. Once the aspiration pneumonia is resolved, supportive treatments may include:

  • Many cats with megaesophagus are switched to a liquid diet because it is easier to swallow. The food is typically placed at an elevated position so that the cat is standing on their hind legs while eating. This allows gravity to work in pushing the food into the stomach. A cat who is unable to eat may require a feeding tube.

  • Medications such as Metoclopramide may be prescribed to improve gastrointestinal movement. Antacids and anti-nausea medications may also be used to prevent damage to the esophagus and improve the catโ€™s overall comfort level.

The prognosis for cats with megaesophagus can vary. Cats with congenital forms tend to fare worse, and many cats will succumb to aspiration pneumonia. Other cats, however, will do well with modifications to their diet and feeding routine.

Why Megaesophagus In Dogs Is Difficult To Treat

The esophagus -- the tube that connects the mouth to the stomach -- plays an important role in digestion. When functioning normally, a reflex causes contractions in the esophagus that move ingested food into the stomach. Other reflexes prevent breathing during swallowing so that food and liquids cannot be inhaled into the lungs.

In some dogs, a congenital defect, disease, or physical blockage can cause these reflexes to fail, resulting in an esophagus that loses all muscle tone and instead of contracting, remains enlarged. This is what is referred to as megaesophagus.

When megaesophagus occurs, ingested food remains in the esophagus, often leading to regurgitation and weight loss. Food that is lingering in the esophagus can also make its way into the lungs, resulting in sometimes fatal episodes of aspiration pneumonia.

Read on to learn all about megaesophagus in dogs.

Causes of Megaesophagus in Dogs

Megaesophagus can either be a congenital defect (one present since birth) or acquired later in life.

In congenital cases, the defect is either idiopathic (meaning the cause is not known) or it is the result of an inherited developmental abnormality, such as a persistent right aortic arch. Aortic arches are blood vessels that serve a function in fetuses, but disappear when the animal is born because they are no longer needed. In some animals however, these blood vessels fail to disappear, and because the right aortic arch is near the esophagus, it creates a situation in which the esophagus is essentially squeezed between the heart and the blood vessel. This causes compression of the esophagus as well as dilation of the esophagus in front of the compressed section.

While congenital megaesophagus can occur in any dog, there seems to be a hereditary predisposition in certain breeds, including the Labrador RetrieverGolden RetrieverGreat DaneGerman ShepherdIrish SetterNewfoundlandMiniature Schnauzer, and Chinese Shar-Pei.

In acquired cases, megaesophagus is either primary or secondary. In primary cases, the cause is idiopathic. In secondary cases, the condition is a result of another issue, such as a blockage in the esophagus or a disease. Diseases that can result in megaesophagus include hypothyroidism, esophagitis, hypoadrenocorticism, heavy metal poisoning, autoimmune diseases, and myasthenia gravis. Myasthenia gravis is a neuromuscular disease and the most common cause of secondary megaesophagus in dogs; it interrupts communication between the nervous system and esophageal muscle so the esophageal muscle does not receive signals that tell it to contract.

Symptoms of Megaesophagus in Dogs

The most common symptoms of megaesophagus in dogs include:

  • Regurgitation

Regurgitation is different than vomiting. Vomiting is when the body actively pushes contents out of the stomach. Regurgitation is when food or liquid falls out of the mouth or throat.

  • Weight Loss

A dog with megaesophagus will often lose weight because food is not making its way to the stomach.

  • Aspiration Pneumonia

    Aspiration pneumonia can occur when food sitting in the esophagus is inhaled into the lungs. The symptoms of aspiration pneumonia include difficulty breathing, difficulty swallowing, coughing, nasal discharge, fever, increased heart rate, weakness, lethargy, and a bluish tint to the skin.

Treatment for Megaesophagus in Dogs

Megaesophagus is typically diagnosed with a chest x-ray or ultrasound that shows an enlarged esophagus, aspiration pneumonia, or material in the esophagus.

Megaesophagus can be difficult to treat. Some puppies with congenital megaesophagus may outgrow the condition, and surgery may be possible for certain development abnormalities. Dogs with congenital forms of the condition should not be bred as it may be passed to their offspring.

Acquired cases of megaesophagus cannot be reversed. For these dogs, treatment is essentially supportive, and may include:

  • Treating respiratory infections with antibiotics as soon as they occur.
  • Managing your dogโ€™s eating.

Ask your veterinarian to recommend a food that will be good for your dog, and adjust your dogโ€™s feeding schedule so that they have small meals frequently instead of large meals once or twice a day.

Elevating your dogโ€™s food bowl so that their head is up while eating can help to move food into the stomach by way of gravity. Many pet parents use a step ladder or Bailey chair to elevate their dogโ€™s bowl.

If the dog is unable to eat on their own, a veterinarian may recommend a feeding tube.

  • Medications may be useful in some cases. Metoclopramide can help to increase muscle tone around the esophagus and stimulate contractions. Antacids can help to reduce esophageal damage, and nausea medications can reduce stomach upset.
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