Night/Sleep Aggression

Hi - We have a 6 yr old neutered male shepherd mix and a 4 yr old spayed female pit bull mix.  They interact very well with each other and are very close (they play together and sleep next to each other).  Within the past year, the male has been picking fights about once a month with the female, but only at night upon awakening.  We believe that he has night terrors/nightmares and then gets abruptly woken up and attacks the female without being fully conscious.  It's difficult to know exactly how things get started, b/c we only wake up to the sound of him attacking her.  Once we were still awake in bed when we heard him whimpering in his sleep and then waking himself up and then jumping the female.  She used to just try to get away, but recently started to defend herself, which makes matters worse.  We now have to keep him in his crate at night so he can't do this.  Please let me know if there are any solutions to this problem.  Thank you.

[Dr. Carol Osborne, DVM]

This sounds behavioral in nature and addressing this to your vet and/or a veterinary begavioral specialist would be my recommendation
Best Wishes
Dr Carol Osborne, DVM