The dogs are already good but I feel like the school DLC could use some more improvements for their ai, whether it can help/hinder gameplay or is just for fun.
First and most important, ability to pet Gunter for possible achievement. After you play fetch with Gunter you should be able to pet him when he's showing the toy that he has in his mouth. This can just be there to make people smile and say thanks to the good boy 
Second of all, Brisket changes. While a good guard dog his current ai is annoying. The moment he attacks you the item you were currently holding gets teleported back to where it originally was and can be REALLY annoying for the trashbags or smaller items. So I propose the ability to fetch with Brisket to distract them OR give Brisket a treat (biscuit) to tame them for a short time..which leads me into my next suggestion 
Third of all, treats. Are you tired of the dogs coming after you then why not go looking around in the school and find some dog biscuits or perhaps a juicy steak to give to the dogs? For clementine and brisket it will temporarily stop their aggressiveness but for Gunter he will probably eat it and do a little trick to say thanks (or perhaps he could dig up a secret item?) 🦴
That's what I can think of so far, hopefully this will be added to add more character to the good boys that are in the school dlc and people will agree with me that these should be added 
also take image of gunter.