WotLK How many pets can I have?

[ChunkyCroc]

Hi guys,
I'm a new beast master hunter player and I love collecting pets. I read that you can stable up to 50 hunter pets but I have no idea how. Is this possible in wotlk? How? When I go to the stable master all I see are the 5 slots I already filled and that's it.

Might be a really dumb noob question but I don't want to release any of my babies :(

[Shred]

All you have is the slots you see when you talk to the stable master.