Thank you for the food suggestions, I have some oxbow pellets on hand from a new chin I got 2 weeks ago. I'll try those.
As for my older one, I put hay in his cage and he showed interest but spread it around everywhere instead of really eating it. When I hold him or if he puts his mouth close to my skin, I do feel some moist air/wetness. Would this be drool from his teeth bothering him?
If chins are getting too many treats or mixed foods, could that fill them up and make them not want to chew or eat hay? Then that leading into teeth problems. Mine was very healthy for the 7 years I've had him, but he's been moved around a lot the past 6-8 months, with me going to college and coming home (I bring him with me). During school I wasn't home everyday with him either. I have been feeding him way more treats than I used to because I feel bad and want him to feel happier and not get stressed or as lonely and treats seem to do the trick.