I copied this from a similar post(answer by mrmr):
Manslaughter, to achieve what you're trying to do you need to tame a pet that "naturally" comes with the ability you want.
For example, you want "Claw Rank2"...then you need to tame a pet that will have "Claw Rank2" as soon as tamed (Beast Lore ability will tell you this...or install an addon for it).
This is just the first part anyway.
Now, you need to use this pet (the one with Claw2), till you "learn" it.
It will happen "randomly" while you fight. I think every time the pet casts the ability you're trying to learn, there is a roll and if you win, you will learn it (a yellow message will appear in your chatframe with something like: "You learned Claw Rank2").
At this point you can abandon your "temporary" pet and get back the one you stabled.
Now, you can open up "Beast Training" from your spellbook and you will find "Claw2" ready to teach.
BUT - my recent plenty attempts to tame pets have yielded pets that start out with no ranks of any spells. so that i cannot learn it to my character, wich i need to learn the higher ranks to my loyal pet.
Any advice??