I have been trying to make a tripping wolf companion work for a while and have been stymied by the lack of Combat Expertise. I recently stumbled upon Dirty Fighting, which bypasses that requirement.
Unfortunately, I need to have my animal companion have at least 4 HD before I can take it, since I am required to bump it's intelligence. This means there are 2 feats used that cannot be adding to my trip plan.
How can I get more feats to aid in my plan, beyond leveling up? Is there any way to retrain animal feats, possibly through some use of handle animal?