Not really sure what is wrong with my 10.5 m/o lab. He seemed fine this morning...went out an did his business like normal, came in and ate like normal. Now this afternoon he seems lethargic, seems like his back end is a little weaker than normal, and he lays down really gingerly (circles about 25x's before plunking down). He also had really bad gas all day. Yesterday morning he threw up, but it was the bile looking stuff...which isn't super uncommon for him. I can push on his stomach, palpate all of his rear joints, and he doesn't bat an eye at it.