Hi Sacha,
Try this link for external:
http://www.yorkietalk.com/forums/sho...5&postcount=19
For internal: Food is most important. It needs to have the correct balance of proteins, oils, fats, vitamins and minerals. If the coat looks dull or not soft, consider switching foods.
Right now on Feliz I am using Dick Van Patten's wet, and Royal Canin, with the following additives:
1. Missing link
2. Flax oil
3. Pumpkin
I hope this helps!
=-)