The file includes fur mask texture that you can use it in particle system to cover the fur under clothes.
The original blender file is Wolf_Character_For_sale.blend, and the second one For_export_wolf.blend which doesn't have any modifer except armature modifier on the models is for export to fbx.
In Wolf_Character_For_sale.blend, you only need the textures Retopoflow_tex and fur_mask, the other textures (eye, tongue, normal maps clothes textures) are for For_export_wolf.blend.