When you say throat problem, is it an esophagus swallowing problem? My rescue boy has this but it is not quite Megaesophagus. He is on Prolisac 1/4 pill every day, Reglan 5 mg. every other day, intestinal prescription dog food both dry and canned though he eats mostly dry with a few tablespoons of canned added with quite a bit of water. He eats standing up-level as he eats from a bowl that is put on a coffee table. This is so the food will go down easier instead of bending over to eat.
He was originally given steroids because the vets were not sure what he had, thought perhaps it was allergies, IPSID, etc. His symptoms were belching and spitting up both water and food. Sometimes he would also have extremely soft stools. The steroids and other things were not working so I took him to an Internist who had a test done that took pictures while he was eating/swallowing. This test showed the esophagus problem. He developed this problem when he was under a year old and he turned 3 in December. So far his symptoms are under control.