rat has hunched back

Question
I have two rats. They are sisters from the same litter, recently the one has seemed to lose weight and walks with a slight hunch to her back.  is this indicative of any illness that is curable because I cannot see her getting sicker and having her sister lose her.  The other shows no similar symptoms

Answer

Weight loss is never normal and when they assume a hunched position, yes, it is indicative of either pain or illness.  She needs a vet.  However, this doesnt mean she has some illness that is not curable. If medical attention is given promptly and treated correctly chances are usually good the rat can recover.  This depends on the vet too, of course, since many vets claim to see rats but are clueless when it boils down to it.  If you need a good vet please let me know.