Short answer: Not really. You don't need to worry about this bug in Classic!
Longer answer: Pets that had mana bars before taming, and weaker combat stats in original "Vanilla" WoW don't seem to display the same bug in Classic. While some quirks from Vanilla were deliberately, painstakingly reproduced in Classic, the developers apparently decided it was not in the best interest of the game, or at least the Hunter class, to reproduce this one. Which is a good thing, since it rendered almost all wind serpents unusable in most situations in Vanilla.
It's possible there's still a very small dps difference between regular pets and those that had mana bars in Vanilla, but it amounts to maybe 2 dps less at level 50 - definitely nothing you should worry about. For more information, see this discussion thread.
For more information on what pets with "caster stats" were, read on. The information below is provided purely for historical interest.
Almost all pets of the same level have the same base attributes. But back in original ("Vanilla") WoW some rare pets had inferior attributes. Because these pets had very high intelligence and spirit, as well as a mana bar on their NPC portrait before taming, we called them "caster" pets. Unfortunately, intelligence and spirit are not useful attributes for a pet. And all of the other attributes -- including health, armor, and DPS -- were lower for "casters" than for normal pets. So "casters" really were inferior creatures.
Pets with "caster" attributes could be identified in two ways:
But how bad were they, really?
After a good bit of research, it was apparent that the only real difference between "casters" and normal pets was their base attributes. "Casters" benefited from scaling, talents and abilities in exactly the same way that normal pets did. So it was at least theoretically possible to make up for "caster" attributes and end up with a pet that you could live with. It's not so easy, though. If you compare the base attributes in the table below with that of normal pets, you can see the following trends:
So pets with "caster" attributes were fairly viable at low levels where the differences in their base attributes were relatively small. And a hunter could help make up for their faults for a number of levels just by keeping up with the passive pet abilities Natural Armor and Great Stamina. But at higher levels, they'd have to spend all of their Training Points on these abilities and they'd still fall short. So if a hunter really, absolutely wanted that very special "caster" pet, they might give it a try -- but it would be a huge challenge.
|Normal||"Caster"||Diff.||% Diff.||Normal||"Caster"||Diff.||% Diff.|