My pom (+/- 6 yrs old), a puppy mill rescue, screams in pain at odd intervals. The vet has checked him thoroughly and can find no cause. Structurally, he is sound, with the exception of a grade 4 unilateral luxation. The ortho says he does not need surgery. This does not appear to be the source of his pain. He tends to hunch himself and stand still when the pain happens. He reacts to touch, no matter where one touches him. He simply screams. We have noticed that he seems to have spontaneous erections, which I have never seen before. Any ideas what may be going on? We’ve run out of specialists.