food for old dog with few teeth

Question
My dog is 13 years old and has few teeth. He had trouble chewing dry dog food but the protein in wet food is causing him to have gas and stomach pain. I have tried every brand of wet food and nothing works. Our vet told us not to give it to him anymore but had no suggestion for an alternative. We have tried the try meaty packs but they don't seem to be enough. He acts like he starving all the time no matter how much he gets. What can we do?

Answer
Try adding water to the old dry food.  It worked very well with an older dog we had.  She had cancer in her upper Jaw.  Our vet was amazed she was still eating.  Of course, she was a typical Lab, very food motivated.  

If that doesn't work, try a careful study of the ingredients.  Few dry foods, but many wet foods contain wheat gluten.  You might be able find a wet food without it.