Pets that have the ability to polymorph will no longer turn red. Some tamers had encountered dragons that polymorphed into humans. Once tamed, the dragon would return to its natural state, except that it would be red. This publish will now return them to a grey/blue state, depending on how its criminal flagging is when the spell wears off.
The gate travel spell has been changed. If you don't have UOE/UOA, you're screwed. Basically, you will go through the gate with all pets, but you'll still look like you're on the other side. You will need to resynch with the server using UOE/UOA or by getting off and on a mount.
Pets will no longer loot corpses. This mainly effects the white wyrm, which will no longer loot (at least in its tamed state. however, it may still loot while wild). Mongbats and imps will no longer loot as well (I'm pretty sure they used to loot).
Follow speed on monsters and pets have been adjusted. Pets now go after monsters at their old follow speed, which appears to be more than adequate. Even while pathfinding, pets have incredible speed. It also makes monsters a bit more of a challenge to defeat.