Megaesophagus in German Shepherds is a condition that results in an enlarged esophagus, the tube-like part of the digestive system that connects the throat and the stomach. The esophagus’ function is to allow transport of food down to the stomach for digestion. When the esophagus is partly blocked over a period of time, it slowly grows in size. It eventually becomes a storage organ, causing backflow of food. As dogs with megaesophagus regurgitate some or all of the food they take in, the condition often leads to weight loss and aspiration pneumonia.
Eli, a German Shepherd puppy suffering from megaesophagus, sits on his customized ‘Bailey Chair’, a high chair designed to help with digestion. Photo by Dan Sherwin via Etsy.
Causes of Megaesophagus in German Shepherds
Congenital
Most cases of megaesophagus in German Shepherds are found to be congenital in nature. Congenital idiopathic megaesophagus, according to research studies, is linked to chromosome 12. Symptoms of this type of megaesophagus typically start showing at around 5 weeks of age when the puppies start eating solid food. The mortality rate in young puppies is high and those who survive need lifelong eating management to overcome this disorder. However, there are cases of congenital megaesophagus in dogs that resolve when they turn 4 to 6 months of age.
Most German Shepherds with congenital megaesophagus have a development disorder in the nervous system, particularly at the lower esophagus. The disorder causes weakness and even paralysis of the esophagus muscles. This prevents food to pass down from the affected point of the esophagus, causing the part above it to enlarge.
Acquired
Acquired megaesophagus in German Shepherds occurs when there is an injury causing physical obstruction in the esophagus. This blockage may be caused by cancerous tumors or the presence of foreign objects. Other causes of this type of Megaesophagus are:
- tumor in the esophagus or nearby organs
- a foreign body that is stuck in the esophagus
- neuromuscular disease that could be caused by canine distemper, myasthenia gravis, and myositis
- swelling of the esophagus
- lead or thallium toxicity
- parasite infestation