It's not a bug. Pets level slow, that and you are probably 20 levels differnt right? Buffalo is lvl 24 i take it? I used to use 1 pet on 2 toons and level them without quests before they would get up high enough to be ok. But yah if you really want a pet you should make a toon to like lvl 22ish and then put the pet on it and then grind and level the pet up that way. It will level the pet up to the point you can use it properly on your lvl 44 character.
The only way to level a pet is to grind on a character of similar level. Quests don't help so you will VERY rapidly out level your pet in GoD due to the daily quests. It takes a great deal of time to work on pets, and that is part of the appeal - they take a great deal of work.
Best practical advice I have if you're not a hardcore player is to level up, make adena, then buy an evolved pet from a farmer once you level past the dailies.