Adopted female with some aggression

[Angelfire]

We adopted a female rottie in Oct and she does have some aggression. Since we rescued a male rottie years ago with aggression (worse then the female) with some work and lots of love he turned into a great dog.
Now back to the female. She is 4 yrs old and spent her first two years with a BYB before she was rescued. She had been adopted but after 2 yrs with another family she was return to the shelter because they could not handle her plus they had another dog who kept injuring his acl. They had said they just couldn't take her on walks because she would want to take off after other dogs on leash. We have this behaviour down to her just whinning at the other dog so that part wasn't bad.
She will give a low growl after I have been petting her but she doesn't bare teeth and then she will roll on her back. It is confusing since she is being submissive at the same time she is growling.
Last night she grab our cat by the head we he got close to her while she was eating (the cat is ok but took off at supper time tonite). I did scold her for her bad behaviour and she kept to herself most of the night in a grumpy mood.
We now have a 8 month old male Rottie and she plays with outside and they have a great time together. If he gets close to her while she has a toy she will growl and bare her teeth at him and a couple times she has snapped at him. He backs down right away but you know young dogs they forget what happen 2 mins ago, so he goes back to her again.
Is this something that could get worse or do we just need to give her more time to adjust to her new home and build trust with us?

[debbiej]

almost any behavior will get worse if it isn't fixed. I would strongly suggest taking a 4 yr old rescue to obedience classes. they are great for bonding and helping her to learn what you want of her. Without training, she is only guessing at her place and your expectations, and no dog is comfortable with that.

as far as the other animals, it sounds to me like she is just setting her boundaries. If she didn't hurt the cat, and the cat was coming to share her food, she may feel she has the right. it would be wise to supervise all interaction with the cat, and allow the dog to eat in peace. as far as the pup, she is warning him too. supervision will be necessary in those interactions too.

help her learn what is expected, set her up to succeed, take her to classes or training, and good luck with your new girl.

[evilshiddenclaws]

the advice given in the above post should be all you need, i just wanted to mention NILIF.

I used NILIF with my dog when i first got him because he was a ballsy aggressive male and tried to push his luck a bit too often but now he's a different dog and i dont have much problem any more

[Angelfire]

She is very obedient and listens to all commands. Without knowing how she was treated by her previous owners, I can only guess that she was mostly negelected. We did have an incident the other night with her and our male rottie over a ball. This time the male did not back down, there were know injuries to either of them. I picked up all their toys and put them away for about an hour. She has stopped growling and snapping at him when he get close to her when she has a toy but I also get his attention away from her toy. I don't believe in hitting animals either as a means of controlling my dogs.
Since the incident the other night she it doing everything she can to be a good girl. The toys seem to be more important to have then getting into a fight over one ball since there are probably about 5 of them on the floor.