current game version: 1.5.0.0.3 (all mods confirmed working)
Horse Editor Tool is a combined LUA and blueprint mod that allows you to directly edit your horses' properties and abilities. It comes with a convenient GUI.
The mod is considered fully featured right now and any future updates will only be bug fixes or visual improvements to the interface.
swap the horse's gender between stallion and mare
age up foals to young adults, age up young adults to adults, or age down adults to young adults
set their stats like Speed or Energy to 100, with a handy "Set All" button for both categories of stats
change coat color, markings, and pattern
set regular/flaxen/silver manes as well as mane/tail length and dye
The mod and its installation instructions are available on Nexusmods. Please read the description carefully to inform yourself about known issues and limitations.