Do they also publish non-horse comics?

Eh, kinda? They have a lot of licensed stuff like the Avatar: The Last Airbender, and Legend of Korra tie-in books, Minecraft comics, the older Star Wars licensed books, but other than those, their main stable is “darker” comics.

There’s a reason it’s not called Light Horse.

Usagi Yojimbo, The Mask, Tank Girl, The Goon, Resident Alien, Axe Cop, Madman, Empowered, Flaming Carrot, Army of Darkness, Critical Role, and Barb Wire.