I had no problem levling at all, pulled 3-5 mobs all day from 85-90 without a problem.
Use mend pet + put a trap down for a free LnL if your survival and a multi to multidot serpent on them all and go to town on them.
did exact samething with my pet from 85 till 90. had him as ferocity, sometimes threw a mend pet on him too make sure he didnt go below 25% when pulling 4+ mobs (8+ if it were those really low hp ones they added). i also had cower on auto cast and he always used that at 50% or sooner if i said so manually. never used cower as much before but its such an awesome tool when i was leveling.
Spec: Beast Mastery.
Pet Type: Turtle.
Pet Talent: Tenacity. Level 45 Talent: Spirit Bond.
You might have to even use Mend Pet on massive pulls.
this. so many people fail to use this talent, in combination with an ACTUAL tank pet. i cant tell you how many silly fail hunters i watch in the Brawler Guild thingie, trying to tank stuff without one. threat is a complete non issue for me, i dont even have to cast MD on my pet anymore, unless of course im AoE'ing. but using SB helps alleviate the constant mend pet casting.
What the hell did blizzard do to hunters? I just started back playing my level 85 hunter and I've noticed that it dies on the same mobs that I use to kill before mop came out. it was times I can round up these same mobs and pet had no problem with them. now my pet is as soft as a babies backside.
You're probably just not playing properly, which is perfectly understandable coming back to the class - its changed a great deal. Hunters are incredible this expansion, as others here have stated. Pets are awesome tanks (especially against AOE mechanics) and you have a number to tools to keep it alive. Mend Pet, Cower. Exhilaration, etc.