This is the third bunny to come down with a problem. One of the bunnies had pneumonia.. another has splay leg but thankfully it doesn't suffer.. it just looks cute and now we went in to check on the bunnies and its back legs have completely given in on it. Its not splay leg. We don't know what's wrong with it. When we lay him on his back his back legs shake like mad.. which we've never noticed with rabbits before.. it seems out of place one of them too.. twisted.. and when he hops he suddenly collapses and ends up lain on his back unable to move but he can hop maybe 2-3 times before that happens then he manages to get back up again but then only manages to hop another 2-3 times before he collapses onto his back again. We have rung the vet and they have told us to keep him hydrated and if still an issue in the morning to take him in tomorrow. Does anyone have any ideas what's wrong? the bunnies are 8 weeks old now.. this little one was meant to go to a loving new home on Monday .. really hope the problem can be fixed and isn't serious .. poor thing..