German shepherds are predisposed to congenital idiopathic megaesophagus (CIM), an inherited disorder where a puppy develops an enlarged esophagus that fails to move food into their stomachs. Puppies with the condition regurgitate their food and fail to thrive, often leading to euthanasia. Researchers have now developed a genetic test for the disease that German shepherd dog breeders can use to reduce the risk that puppies in future litters will develop the disease.