Percy Peapod too has stomatitis. He goes in for regular steroid shots for now and an added round of antibiotic. Clavamox seems to work the best. Alternative is Antirobe. The steroid lasts about 6-8 weeks. I keep a very close eye on him and know the symptoms of when he needs to go in for a shot. We also weigh him every time to make sure he is keeping weight on.
I took him (and the rest of the gang) completely off any kind of treats and food other than Science Diet. And tuna (one of his favorites) seemed to really cause problems. But switching to a quality food really helped him. He does still eat crunchy food, but the smaller the bite size the better. Round pellets are easier on his mouth. He doesn't like soft meat that can get stuck in his teeth and cause pain.

He eats soft food (mixed with water so he pretty much licks it up) and has shed a couple of smaller teeth, but my vet hasn't said that it has gotten to the point of needing teeth removed.

Hope some of these suggestions help. We are sorry you have to deal with this with your little Precious.

The Tribe