A 10mm glock would be a pretty good choice for most anything smaller than a brown bear.
A .44 mag would probably be overkill for either lions or wolves - just make sure go with a bullet designed for 4 legged foes rather than 2 legged.
In all honesty, if you're comfortable with, and shoot your 9mm well it would probably work just fine.
With a lion, if you see it and shoot it, it's almost certainly going to run away. And, if it attacks you before you see it, it won't much matter what's in your holster.
I wouldn't worry too much about wolf attacks though. You're statistically quite a lot more likely to get killed by bees (or lighting for that matter) than wolves. If you don't have livestock, they generally stay away from other predators. If you see them around, a couple shots into the ground would probably do it. Just don't act like prey. Like all canines they're hardwired to chase things that run away from them, and they're quite a lot faster than we are.
si vis pacem para bellum