Someone asked this question in the forums yesterday, in terms of the most overall DPS.
Cats outdps boars in the early game, and it scales. The survivability of a boar is radically greater, but if as BM you're also getting Endurance Training and Thick Hide, you will probably be able to get away with that for balancing the cat's survivability...even more so if you train Great Stamina and Natural Armor.
However, think twice. A cat will give you increased DPS, yes...but the survivability of a boosted cat still won't touch that of a boosted boar, and on top of that, a cat has no way of getting you the initial aggro that you'll get with a boar. As BM currently, with Charge my boar can get 3.5k aggro inside 5 seconds or so. Feigning for me is largely a thing of the past; I never need to do it, especially with Intimidation.
Instead of getting a cat for the DPS, my own advice would be to get a boar for the survivability, and for DPS, work on your own ranged weapon and shot rotation. My boar's DPS is still 117, and with only my second gear rotation, (Steady, Auto, Steady, Auto, Arcane, Auto) I can clear 300. Plus I can tank adds with a much greater degree of confidence than with a cat...Cats die a lot sooner. As it has been said, the DPS of a dead pet is 0.