WHY IS ALL FOUR OF MY DOG LEGS STIFFENING OUT?

My dog is an Akita mix and she is 6 months old. her legs would look shaky and the muscles in her legs moves in an unnatural way then her legs would stiff out for about 30 sec and then the will go back to normal. sometimes it gets really bad and all four legs will be stiff and then she would collapse because she can't hold up her self. days when it is bad she would just lay all day. it does not seems like if she is in any pain but it is painful to watch her in that condition. i took her to the vet an they say it might be seizes but it does not add up because she is not out of it she still knows what is going. they want to give her a shot for seizes but they have to nutter her. what else can i do to get her well again besides the shot?