They moved pet specific abilities to level 20 early in cata
Every pet can choose all of those roles and you can change pet specs until the gates open so there basically is no difference other than looks.There is a difference what pet you choose below 20 (check your pets for the names of abilities). Choose 2 of 3 depending on your role.
Cunning to protect an ally (pet takes some of damage and no crits).
Ferocity does extra dps + dash + the ability to resurect pet instant once every 8 minutes (heart of phoenix).
Tenacity has a charge + 1 sec stun.
Oh and pets like the Burning Battle Boars or Consumed Thistle Bears need to be put in stable and taken out before these abilities will "stick" on your pets action bar, just a heads up.
There is a difference what pet you choose below 20 (check your pets for the names of abilities). Choose 2 of 3 depending on your role.
Cunning to protect an ally (pet takes some of damage and no crits).
Ferocity does extra dps + dash + the ability to resurect pet instant once every 8 minutes (heart of phoenix).
Tenacity has a charge + 1 sec stun.
Oh and pets like the Burning Battle Boars or Consumed Thistle Bears need to be put in stable and taken out before these abilities will "stick" on your pets action bar, just a heads up.