Mateo's Hurt

We're not sure what happened, and I wasn't home when it did, but when I came home this evening, my brother told me that Mateo seemed to have a permanant limp. He was unwilling or unable to use or put any weight on his left rear leg. My brother said that he wasn't sure, but that he thought it might be hip dysplasia since Mateo had earlier been able to do some pretty crazy things with his hind legs like do a complete split much like my roomie's cat would do. So Mateo's been really quiet this evening and has remained for the most part on my brother's bed without much movement. Even petting him, hugging him, talking to him usually doesn't even make him open his eyes. Only when someone new opens the door does he open his eyes and raise his head to see who it is. I'm planning on taking him to the vet in the morning, and hopefully we'll find out what's wrong. He's only a puppy, but they can get hip dsyplasia too.. And he's been jumping on and off the furniture and standing on his hind legs for a while now which can instigate or provoke this occurance. Hope it's not that.. but I guess we'll find out for sure in the morning. It's really sad to see him just laying really quietly on my bro's bed. He's almost never this calm and still. Usually he's utterly insane bouncing all over the place, play-fighting with Vasco or Hope. I suppose there's nothing much to do but wait and pray.