As animals are limited by their Intelligence for the number of tricks they know, is it possible to teach a new trick to an animal and have it replace one the animal knew?
For example, one of my character has a combat trained dog, and I’d like it to have the attack trick a second time, maybe replacing defend.
This is for PFSOP.
If you have the Ultimate Campaign book (which has rules for retraining), talk to an experienced PFS GM and ask if they will allow you can retrain your dog's trick as if it was a skill. It's not in the rules per se, but it's not an unreasonable stretch.
If you do not have the Ultimate Campaign book, you have no options for retraining.