[header] How to care for rex rabbits [title] Take your rex rabbit to see a veterinarian. [step] Try to find a veterinarian who has an interest in rabbits and who is comfortable providing veterinary care for rabbits as well. You might need to seek out an exotics veterinarian or at least find a veterinarian who has done some ongoing professional development on rabbits. 
Take your rex rabbit for annual checkups and watch for any signs of a problem. If your rex rabbit seems like he is sick, then take him to see a veterinarian right away.