So a little background.
The dog was raised in a house that had a cat but the cat never really appeared when she was in the house up to about 2 or 3 months old, then moved to another place where there are no cats at all. The only cats she sees are outside, away from her and she usually barks at them and gets a bit anxious over it.
Well, this dog isn't mine but my sisters, so I rarely have interaction with the dog. However, when they bring her home, she usually gets a bit crazy about the cats, so we put them up in the basement. She will paw at the basement door, knowing they are there.
This is the part that I'm worried about, her behavior towards the cats are scary. So, out of curiosity to see what she would do or how she would react, we put a leash on her and put our brave kitten in a crate. We kept them separated but as soon as she saw the cat, she went NUTS. She made this loud whimpering sound and fought the leash to get to the cat. We kept them away for a while and she just continued this for a while till we got her to chill out. All my sister did was touch the crate and she just went off again. Also in between when she stopped fighting, she just stared very intently at the cat, she wouldn't move at all but was shaking and wouldn't take her eyes off the cat.
Now, just a different story but I have a friend who has three outdoor dogs. They have a small barn just a walk from the house and the dogs always follow them there. Well, at the small barn happens to be quite a few cats in which the dogs consider to be chew toys. The dogs have killed quite a few cats that they have there and the exhibit the same behavior as this dog has. I've never seen them actually go after a cat but I have seen them watch them intently and whimper quite a bit.
So, after saying all this. I have a feeling that it's best to say she isn't a dog that should have a cat around because of her behavior. However, my sister loves cats, so is there anyway to attribute it to her still being young with puppy behavior and she will grow out of this, or can they slowly...and I mean very slowly introduce her to a cat so that she doesn't hurt them or it hurt her?