Pet taunts are like every few seconds + massive threat, not like a normal tanks where it only gives massive threat "to match" whoevers up top (and near nothing if no ones up there)
My survival hunter pet cat threat does about 5500-6000 threat 10man/25man groups and suicides pretty easily if left on (dam buggy pet abilities keep turning it on and or cower)
Growl - Spell - World of Warcraft