Sculptris has no tools for fur.
You can use Blender to add fur to your model. You should find tutorials via google/youtube.
Also if you want to animate a model created in sculptris you should think about retopo. There's a video thread, posted by justdeletedguy in this forum(don't know what page) where retopo is explained for Wings3D.
You can use textures to create a cartoonish semi-fur look by adding bump and slight color variations to the surface.
Often, at least if you're not going for realism, this looks better. Especially if you don't have any experience with hair/fur in 3D.
Also hair/fur is a resource-hog, if you don't have a good computer, rendering hair/fur takes ages if you want it to look good not to mention realistic.
I'd say try it in Blender and you'll see if it's for you. Fur isn't as hard to make look good as long hair, so take a shot
