You want the Horse Dust and mud to work? There is already a mod exisiting for it and I'm using it with pleasure. I use it together with FOV Tweak for Horse riding, to have the visuals that way, that I can see how Roach is raising dust, water and mud.
https://www.nexusmods.com/witcher3/m...ab=description. I do not know, if I use this version, because of a few little bugs, maybe I have another version. I will check this out on my PC later. If my version is different, I will upload it for you, so you can choose between two and select the one, which is better fitting for you.
https://www.nexusmods.com/witcher3/m...ab=description
This is the one I'm using, but without the scripts-Folder, so just for the water, snow, dust, mud-animation. Use FOV-Tweak and set it for Riding to 75 and it will be visuable more noticable.