If you have already befriended the wolf, then you know you can level him up in camp by giving him meat...
We'll once you give him meat it disappears, right? WRONG!
After feeding him meat, go straight into the FORGE screen then go back out, and the meat you use should return!
Do not leave camp without visiting the FORGE first in order for this to work, even if you don't make anything.
I quickly leveled up my wolf to his max by using this trick!
I hope they don't fix this bug in an update because the wolf is super useful in this already tough game.
Also the wolf stats stay the same even if you get tossed out of the tower :-)
EDIT: I read that this has been fixed in the new update...sorry :-/