It sounds like your dog might be suffering from early symptoms of a condition known as Megaesophagus. This can be caused either by disease or nerve damage, and can sometimes be hereditary in certain dog breeds. This condition normally affects larger dog breeds, is difficult to diagnose and has limited treatment options. If symptoms present themselves while your dog is a puppy, the disease is normally inherited.

When food or water is detected in the esophagus (the tube connecting the throat to the stomach), a normal neurological reflex will cause a muscle contraction and relaxation that transports the food into the stomach. Other reflexes prevent breathing during this swallowing process to protect the lungs from aspiration. When this process is interrupted by Megaesophagus, the esophagus loses its ability to transport food. The most serious complication is that digestive fluid will at some point pool in the esophagus. Since a dog’s trachea connect to the esophagus from the underside, this pooling generally results in aspiration of digestive fluid, leading to pneumonia.

Normally an affected dog will exhibit other symptoms such as inability to swallow large mouthfuls of food, fever and foul breath. It is important that your dog has a thorough veterinary examination in order to diagnose him. Before this happens, you must make sure that your dog is receiving adequate nutrition (food and water) and document any additional symptoms – this will help your vet. If he has Megaesophagus your vet will discuss how to prevent further complications such as pneumonia.