My dog did that this morning! She is a Bichon Frise, and she started screaming so loudly, I rushed to the den. I picked her up and her paws were drawn, she was in severe pain. I was crying, saying Oh God, Oh God. I thought she was dying. She is nine years old and she is my baby. I rushed her to the vet, and after a two and half hour wait, he said she had swollen shoulder. Inflamation, and evidenly jumped from chair to couch and hit a nerve. Came home with a shot and meds, ate all of her dinner tonight. The vet called to ask how I was, he knew I was close to losing it today!!! Thank you, God! She is okay.