What I'm saying is that as the game is now, untamed pet mobs do not teleport. They have no owners to teleport to.
And of course they spawn. Breeding for them was just introduced, so they probably haven't been made to rarely spawn like the other passives yet.
For the record, animals of any type can still respawn if the conditions are right. They are persistent now, and spawn upon chunk creation, but new herds can still spawn after the fact, if the world is too empty...like if you're killing them all the time. I used SPC's "killnpc all" command in a 1.1 test world yesterday, and watched 4 new pigs spawn right in front of me, not even 10 seconds later.