These are the approved feats for Animal Companions, Special Mounts, and other animals you own and train with the Handle Animal skill:
Ability Focus
Agile
Alertness
Athletic
Awesome Blow
Blind-Fight
Cleave
Combat Reflexes
Diehard
Dodge
Endurance
Far Shot
Flyby Attack
Great Cleave
Great Fortitude
Hover
Improved Bull Rush
Improved Critical
Improved Initiative
Improved Natural Armor
Improved Natural Attack
Improved Overrun
Improved Precise Shot
Improved Sunder
Iron Will
Lightning Reflexes
Mobility
Multiattack
Point-Blank Shot
Precise Shot
Rapid Shot
Run
Shot on the Run
Toughness