Hiya, when mine had a collapsed mantle I kept him in a very low tub so he couldn't climb. I kept him warm and humid and coaxed him out by wetting him to try and get him to eat. He made a full recovery and I hope yours does too
Hi stiff, welcome to the forum. Sorry your snail is not doing well. A pic will be helpful for us to figure out what's going on. The dryness is worrisome. It is not usually associated with mantle collapse, as far as I know. It may be something else going on.
He might have had a fall. I wouldn't know. The edge of his shell is very rough compared to how it normally is. He seems to be improving since I posted this. I've been keeping him wet and encouraging him to eat.
If it is a fall, it would have happened in his tank. I've never dropped him and I'm very careful when holding him to make sure his shell is supported. I think it feels too heavy for him!
I guess just perseverance with the water and food is the key then? I've put him in a shallow container already and He is getting offerings of fresh food as normal. His tank is way more humid than normal too.
What is the best bedding to use? I'm worried that I'm not using the best stuff.
I don't know of any special substrate to use for mantle collapse. There are many acceptable kinds of substrate, with no single one particularly superior to the rest. I'm partial to coir, but there are others just as good.