I am looking for advice regarding possessive behavior or "resource guarding" that I am finding in my new chichi. She is, according to the shelter she came from, 2-3 years old, looks older to me, I'm not sure how they tell exactly but that doesn't really matter. She is the absolute sweetest, calmest animal I've ever had. Seems like she wouldn't hurt a fly. She is loyal to us already with the exception that she hates the cat, but is already fighting urges to chase him when he walks by.
Our concern is this guarding behavior I've seen occasionally and now know it's an actual trait, not just a once or twice occurrence. She ONLY shows this behavior toward Maya, the puppy. Furthermore, she only guards certain items. She doesn't even care if Maya comes and eats out of her bowl at breakfast time. I got these thin rawhide dental chewies for Maya awhile ago, and there were a couple laying around. The first time Navi got ahold of one, she didn't let Maya come anywhere near her. Showing teeth, growling lowly, head ducked. Needless to say Maya got the hint, and didn't go near her, even though Navi had "her" toy. When I saw this I immediately took it away from Navi. She also shows this behavior with a braided rawhide stick (yeah, I'm seeing the pattern... rawhide), that again, Maya was previously just playing with. Regardless, how do we begin the process of reversing/correcting this behavior? I've read here and there what I can from the internet. But A lot of the info is regarding dog vs human, and this is only dog vs dog. She is completely "submissive" to us about it. But tonight was the first time I saw her actually snap and bite very rudely to Maya as she was trying to get her toy back that Navi stole (I didn't realize until tonight that this was actually an issue). I should note Maya is oblivious (ahem.. spoiled) and didn't even know what to make of that reaction, it scared her. OTHER than those few incidents they are best friends.
Sorry for the length of this post, I would just like any advice knowing you have all the info for my situation. As far as what I'd like to try, I was thinking of putting up all the rawhide's (which sucks because those keep Maya busy for HOURS lol..) and maybe even all the toys, at least for now, and giving them back maybe one by one to figure out which other ones may cause the problem. As far as correcting the behavior in the moment ie if it happens again, what is the correct way to show her that it's not ok? Another thing, she isn't into ANY toys that are not of some sort of edible matter. She doesn't like stuffed animals, squeakers, balls, etc. She is just laid back and likes to lay down (which also makes me think she's older but maybe thats just her), so I don't have a lot of options for toys for her to substitute for the yummier ones.
Thanks for any help!
PS - Here's a picture of Navi.. borrowing Maya's clothes (typical sisters)