Two of my dogs are yorkies and one of them is a silky. Our silky is actually smaller than both of our yorkies, so size alone does not determine yorkie vs. silky. Our silky is definitely longer than tall. She has a longer snout which is also shaped somewhat different from our yorkies. Her ears are also higher on her head than our yorkies. Her hair is different. Even though she looks very similar to a yorkie, there are definite differences. Heck, most people think she's a yorkie too. If you research yorkies, silkys, and austrailian terriers, you will begin to see some of the australian terrier traits in the silky.
If your dog is longer than tall, it could very well be a silky. If the dog is about as tall as it is long, then very likely that it is a yorkie. Look at the other traits of both breeds and see if you can tell which it most closely resembles. I will tell you that they are both wonderful dogs though!
Our other dog is a 6 lb. maltese, and she thinks she rules the roost! She definitely has an alpha personality, and her and our older yorkie constantly battle for that alpha spot. Ginger is getting a little older now (almost 11) and tends to let Lilly (the maltese) get away with her antics more than she used to. Crazy little dogs. They all have different personalities.
