I have a 2 yr. old intact male EM who has never shown any weakness or lameness in the rear. Yesterday my husband took him out in the yard to play soccer. Carson went after the ball and my husband said his rear collapsed under him. He tried to get up but was unable and just lay down. He never made a sound, was perfectly alert and was up in about 3-4 min, moving well with no limping or lameness. He had an incident about 1 yr. ago when he was swimming but we thought he just had a leg cramp after being in the water for about an hour (do dogs get leg cramps?). I have a vet appointment, but I just thought I would put this out there.