Resource guarding under control... Kinda...

You haven't really described the situations where this happened, so it's hard to offer advice.

I thought you were a trainer?  What does your mentor have to say about this, since I assume they have the capacity to witness this first hand.

This usually happens when I'm doling out treats or when another dog comes running up to say hi to me. Maze can be on the other side of the field (or where ever we are) and as soon as she spots another dog near me, she'll come running, place her self between us and growl at the other dog. If I have treats and every one is in a sit, she'll lip curl at the nearest dog.

I am a trainer, however I normally deal with puppies. Socializtion, man handling (for vet visits), stuff like that. I also do basic obedience. Behavior stuff is kinda outta my domain at the moment. Besides, Maze is the first dog I've encountered with this issue. My mentor at the moment is going through some life stuff and I don't want to bother her with this, since it's not really life threatening and no one is getting hurt. And no, they haven't had the chance to see Maze do this since I don't bring her to work all that often, and when she is with me, I'm working her and no one else. So there really hasn't been an opportunity for this behavior to be witnessed.

I'm not a trainer, just an owner. My thought on this is to put her in a down, not a sit, when other dogs are approaching. In a sit she is still able to show off her aggression attitude and body language, in a down they tend to be more subdued, they have less control to exert their dominance to others. Even her lip curl is going to have less affect in a down and if she were to leap up you would have more time to grab her then when she is already at their eye-level in a sit. (say, if she went after the other dog.) You can also use a tie-out, tying her a couple of feet away from you, so you can safely be greeted by another dog, verbally correct her aggression, without having her leash wrapped around you if she does go after the dog. Correct even the lip curl, in my opinion, no attitude is allowed. You have a right to pet other dogs, she doesn't own you. She needs that message from you. Ok am done rambling.

 Does she only do this when you hand out treats to other dogs or just you with no treats?

oranges81

This usually happens when I'm doling out treats or when another dog comes running up to say hi to me. Maze can be on the other side of the field (or where ever we are) and as soon as she spots another dog near me, she'll come running, place her self between us and growl at the other dog. If I have treats and every one is in a sit, she'll lip curl at the nearest dog.

Ok and then what do you do? do you still give her treats while she is displaying the behavior? She should not be given anything until she is clearly clam, it does not matter if she is sitting, laying down, upside down, etc. What matters is the state of mind that she is showing, she could be still displaying guarding behavior in any position you place her. She needs to learn that clam behavior is what actually gets her the treats, not guarding behavior

tiffy

 Does she only do this when you hand out treats to other dogs or just you with no treats?

Either or. I just have to in the same area as her, and she'll act this way.

espencer

oranges81

This usually happens when I'm doling out treats or when another dog comes running up to say hi to me. Maze can be on the other side of the field (or where ever we are) and as soon as she spots another dog near me, she'll come running, place her self between us and growl at the other dog. If I have treats and every one is in a sit, she'll lip curl at the nearest dog.

Ok and then what do you do? do you still give her treats while she is displaying the behavior? She should not be given anything until she is clearly clam, it does not matter if she is sitting, laying down, upside down, etc. What matters is the state of mind that she is showing, she could be still displaying guarding behavior in any position you place her. She needs to learn that clam behavior is what actually gets her the treats, not guarding behavior

I'll turn my back to her and ignore her. She gets nothing until she gives up. Usually it ends up that everyone else get treats (or pets) and she ends up with nothing cuz she wouldn't stop.

I can have her lie down but she's more tense and on edge when I do this.