I have two horsefield tortoises both roughly 3 years old and one seems to be a lot less healthy and lazy. The unhealthy one is bigger but they are the same age. What are these markings on the shell! I can tell they are bad as the other doesn't have them and it's worrying me you can see the healthiest one from the picture of them both. The healthy looking is very active, always up out of it's shell until the lights are turned off but the other only comes out for food