Something else to consider.

A lot of active horse people get an entirely to active dog. Your already very active with your horse , getting a dog with similar energy level is going to be a huge drain on "you". So look for a dog thats medium low to low energy.

"Blessed are the flexible for they shall not get bent out of shape"
"You can discipline and Discourage or you can Discipline and Encourage"
"Gentle in what you do , But firm in how you do it"