My parents used to put vegetable oil on their yorkie's food to help her skin and coat until they learned about Missing Link Supplement. You sprinkle it on their food and it does wonders for their skin, coat, and it really aids in their digestion and their ability to recover from surgery/injury. If you wanna check it out, here is a link:
http://www.designinghealth.com/produ...ucts_main.html