[Shmoes Mommie]

I have a 8 month old Yorkie. Shes my 3rd yorkies now. She is the sweetest thing loves people, loves dogs. Anytime a dog comes around she just rolls onto her back and is very very sumissive and lets the dog smell away. Both new dogs and dogs she knows. All of a sudden one day were at the dog park where 25 of us go different days but same time, and i went to give a treat to another dog like i always have and she lunged and snaped at the dog. It was a dog that she already knows well. A few days later she was on my lap when i was sitting and i went to get a couple stickers off of her and a dog got about a foot away and she did it again. Different dog but still a dog she knows well. Since then i dont put her on my lap because i know she was trying to protect me. But what she does is if she is in front of me on the ground and a dog gets too close she jumps up on her hind legs and does this lung/snap thing. Its the strangest thing since she is such a sumissive dog. Yesterday i worked on squading next to her and if a dog came close and she didnt do anything or if she was sumissive then she got her favorite treat and only that treat at that time now, but if she lunged or snapped i made a distinct noise and ignored her. So her punishment would be not to be by me and me ignoring her. Please if anyone has a better idea i would love to hear. Im actually in dog training school now about half way done but we havent been taught this and its different when its your own dog. thank you