Although you can't change the type of coat your yorkie has, I have recently done some things different that have made a HUGE difference in the manageability of my girls coats as well as the appearance.
I stopped using Grizzly Salmon oil and instead give them each 1/4 tsp of melted coconut oil (extra virgin, organic) with their dinner. Then, when I bathe them, I also melt about the same abount of coconut oil and add it to the shampoo in my hand and then work it really well into their coat/skin and let it sit for about a minute. I use Buddy Wash for Sissy and Minksheen for Angel. I then use the BioGroom Silk Conditioning Rinse on both of them.
In between baths, every other day I use the BioGroom Mink Oil Conditioning Spray. It does not make them greasy, continues the shine and also makes the coat very manageable. I have several friends who have known the girls since I got them and they have all asked what I've been doing differently lately.
Sissy has a very cottony coat that is brittle and doesn't grow, and Angel has a silky coat that tangles easily. With this regimen, Sissy's coat has started to grow and Angel is so easy to comb out!!!!!
BTW - coconut oil has many benefitial health properties to it that the Omegas do not.
These photos are after their weekly bath....
Sissy
Angel