I agree with lukelightning.
The Dire Wolf is unable to use most standard items in the core books. No potions, wands, rods, staves. Armor must be custom made. Weapons must be custom made. No ranged weapons. Majority of wondrous items unusable. The wolf has slots but they must be customed made.
The net effect is that you cannot give the wolf the hand-me-down second class items that would normally flow to the cohort. Equipping the wolf to survive will cost 50%-100% more than a normal cohort.
It is not a small thing that a cohort cannot drink potions nor pour them down the throat of a fallen PC -- the standard activity for humbled fighters. Or even pull out a bow. When the wolf gets chewed up and must pull off the front line, he becomes completely useless and may require rescuing.