A druid or ranger gains a +4 circumstance bonus on Handle Animal checks involving her animal companion.
In addition, a druid’s or ranger’s animal companion knows one or more bonus tricks, which don’t count against the normal limit on tricks known and don’t require any training time or Handle Animal checks to teach.
Untrained
If you have no ranks in Handle Animal, you can use a Charisma check to handle and push domestic animals, but you can’t teach, rear, or train animals. A druid or ranger with no ranks in Handle Animal can use a Charisma check to handle and push her animal companion, but she can’t teach, rear, or train other nondomestic animals.
I'm thinking of instituting a house ruled new animal trick called Loyalty.
Loyalty (DC 20)
Animal Companions with this trick provide their owners/handlers a +5 circumstance bonus to Handle Animal checks.
My reasoning behind this is that a druid or ranger with a low Charisma score, and zero ranks in Handle Animal (before you nerdrage on me about how all druids and rangers should max out their ranks in Handle Animal, please realize that it is a very distinct possibility that a player is focusing their skills elsewhere because of their particular build, and not everyone plays the game the way you do) could have a 25% chance to waste a move action telling their animal companion to attack, etc. If one of the animal companion's bonus tricks was Loyalty. It would greatly alleviate that problem, but does force the owner of the animal to "sacrifice" a trick slot for their lack of Handle Animal skill.
This idea is in its infancy so all constructive feedback is appreciated.