If you're using the CEPv2 and need a quick and effective method for dealing with horses, this is the one I created. It's been tested in several different modules - both official and custom.
Allows the PC to mount and dismount animals without the need to place special objects or perform any elaborate radial actions.
A conversation to mount, an item to dismount (horse tether), item event script, and mounting script are included. Only a few steps are needed to install the file and a readme with notes is included.