I've helped raise two Golden Retrievers and I personally would not recommend Goldens as a breed to pair with a Yorkie. Their personalities are great and they're friendly with other dogs, but they have NO concept of their large size and they are very mouthy. Also, they are bred with a very,
very strong instinct to carry dead small animals around in their mouth...
It would not be an aggression issue, it would be sheer clumsiness. One of my parents' Goldens, Bella, accidentally broke my mother's foot after landing on it during an exuberant hoppy greeting. She's the size of a small lion and along with her brother Vito she is constantly jumping, rolling onto the ground, wrestling, and charging around tripping over small objects or her own big klutzy feet. They could easily hurt or kill a Yorkie by accident.
If I were you, I would get a Bichon Frise. They're bigger, but not
too big. My neighbors have a brace of them and they're lovely little dogs.
Besides, there is no guarantee that a large dog will protect you in a street fight, anyway, unless you get a breed which is completely unsuitable to pair with your Yorkie. Carry mace instead.
