Hi Moniqua,
Read your posting and obviously you have an issue with your dog but IMO its not an "aggressive dog" issue. Renee made a valid comment about the usage of the word "Aggressive" which is a dog that wants to bite you and chase you without backing down. - from the sounds of things you have a Mastiff, not a typical Mastiff but one that is very stubborn (which the breed is) and one that doesn't seem to have much direction in the house (fundamental/foundation obedience) and definitely no patience which from reading one of your postings, you have lots of.
"first she comes to one side of me, then the other... she continues this for 2 minutes, then leaves the room... she comes back with a shoe AHHH can't really ignore that so I get up take the shoe and put it on the shelf... Then the entire thing starts all over 20 minutes later I had 3 shoes, 2 boots, the dust pan and a dirty sock on the shelf ... she finally got tired and lied down, so I treated her and played with her for a few minutes"
This is your actual posting so lets break it down. "first she comes to one side of me, then the other... she continues this for 2 minutes, then leaves the room... she comes back with a shoe AHHH can't really ignore that so I get up take the shoe and put it on the shelf"
- Your dog walks into your room, restless and looking for something to do. If your dog was fundamentally/properly trained in obedience you can simply give her the command to "down" since she's not she walks for 2 mins looking for something to get into which you allow her to. She then proceeds to leave the room and comes back with a shoe. Obviously you can't ignore this so you put the shoe up yet you never mention at one time that you correct her for this behavior, that would be problem #3 from my count.
Problem 1 is no formal obedience training for a dog that is going to be 140lbs is not acceptable
Problem 2 is you allowed her to build frustration, dogs need direction and you allowed her to be a dog and she found a shoe
Problem 3 she proceeds to bring a shoe to distract herself and play w/you but obviously a no/no and you don't correct it.
"Then the entire thing starts all over 20 minutes later I had 3 shoes, 2 boots, the dust pan and a dirty sock on the shelf ... she finally got tired and lied down, so I treated her and played with her for a few minutes"
Here is the second part, you mention that after 20 minutes you had 3 shoes, 2 boots, dust pan and a dirty sock from the shelf. Again, I don't know if you corrected this behavior but if you did it right then you wouldn't be up to that many items in your room. Your dog is bored, lacking patience and has no direction and is looking for you to give it to her. Like children that does negative things in this world, its a usual sign of them seeking attention. Pandora's doing just that. "she finally got tried and lied down, so I treated her and played with her for a few minutes" - WOW, you actually enabled her. You forgave and gave her treats for this wrong behavior and wonder why your dog is doing what she's doing. You should of played with her and corrected this in the first place then give her a treat for when she does it consistently but not what you did.
Problem 4 you never mentioned a correction for the items she brought into the room, lots of items at this point.
Problem 5 and the worst of them all, you actually praised her for the behavior she did by playing with her and giving her treats.
I would suggest that you seek professional help in this matter, you need to understand what kind of dog you have and get her trained. Find a trainer that understands the breed, think about it like this. Just because he/she knows how to fix a Mercedes doesn't mean he/she knows how to fix a Toyota. Same can be said for a trainer, most work with Labs, Pointers and such but haven't been around a Mastiff. They need a firm hand, not positive training. Dogs like this need direction, firm handling. Your dog is simply a "Baby Huey" in that she's physically a big dog but mentally she hasn't caught up with her body. Aggression is not the problem, your allowing her to be a dog and she's acting as if she owns the place. One of my sayings to my clients is this "treat a dog like a human and she'll turn around and treat you like a dog" think about this, your dog is doing just that.
Thanks for reading this and hopefully this helps. I'm a dog trainer located in Southern California working with many large/exotic dogs. Tosas, Neo's, Bourdeauxs', Mastiff, Boerboels, Filas, Ovtcharkas, American Bulldogs, Cane Corso, Presa's and the list goes on. Let me know how everything goes.
STDT
Maybe try positive motivational training instead of force? Mastiffs are big, strong, stubborn dogs - they'll do it because they love you and maybe there's some nummy food in it for them. If you can make her sit, you can try teaching her the 'down' command by holding the treat in front of her and slowly bringing it to the floor, having her follow and going 'down' to get it. It may take a few times, but I'm sure she'll get it eventually.
