I really need some advice! my BF and I have lived together for 3 years. he has a pit bull, male, fixed age 5. I have a shepard / collie mix, female, fixed, age 10. They have always gotten along like best friends. Until recently. We moved 3 months ago, then my BF left for a week.. the pit bull all of a sudden became aggressive to my shepard mix ..stalking and attacking her. I kept them separated till the BF got home, the pit seems to have settled down and they seemed to get a long again. every now and again I think he is stalking her or just stands there and looks at her. Now my shepard, who already was a little bit clingy wont leave my side, even if she has to squeeze into a place that she doesn't fit. she now jumps on the bed at night a tries to sleep on me or as close as she can get. ( this is new, she used to just sleep down at my feet) ... any advice? I feel so bad for my dog, she is old and seems so unhappy.