Your pet's talent points are calculated using this basic formula:
(Loyalty level - 1) * pet level
So, essentially, if your pet is at max loyalty (level 6) then you minus one to get five and multiply that by its level (48)... This ends up as 240. Now subtract whatever points you've used to train abilities and armor for the pet. This will be where the points have gone.
Two levels ago, using a pet level of 46, your total talent points (if unspent and assuming max loyalty level) would have been 230. Between those two levels there hasn't been a large change. Have you spent any points in that time?
Talent points don't gather in infinite amounts, growing with each kill or level. Assuming loyalty level 6 and a pet of level 70, the talent points he will have (without anything trained) should equal 350.
So, choose which abilities and buffs you want most for your pet because you'll never be able to get everything.