If you want to make a texture Transparent you can go in GIMP, for example, and go to Layer>Transparency and then click "Add Alpha Channel". If that's already on or when you've clicked that for the fur texture, go to the same section and click "Color To Alpha". The white bar is the color you want to make transparent.
Leave it on white, obviously, then simply click "OK".
Hope this helped somewhat? :{o
