I have a 4 yr old RT who has developed a dip in his shell. I am not sure as to why. He eats green leaf lettuce & radicchio and has proper lighting and water accessibility. Any insight would be greatly appreciated, thanks!
Welcome! When you say developed do you mean over a long period of time or just recently. Does he have access to UVB light and get regular exercise? Vitamin supplements?
You need to feed him a much larger varied diet. You also need to be giving him some calcium with d3 at least 2 times a week. He needs water available 24/7 and you should soak him about once a week. It looks to me your tort has MBD. What kind of UVB light are you using? The tube fluorescent type is best for Russians, but the UVB is on,y good for 6 months. When did you change it last? The mvb are only good for a year. I would get your tort on a better diet and get him outside for some good sunlight.
That dip indicates that the tortoise's bone structure is collapsing. This is a very serious problem with your tortoise and he might very well die from it. He needs immediate attention.
You say he has the correct lighting, but to be sure we're all on the same page, what light are you using? Does he ever get real sunshine?
Your tortoise needs an immediate infusion of calcium and sunshine. If you can't provide the sunshine, then he needs an expensive UVB light...not a light that has been burning for over 6 months, but a new light that is giving off lots of UVB.
Calcium needs the UVB from the sun or an expensive light in order to work. The tortoise takes the UVB and makes vitamin d3 out of it. Calcium/vitamin D3. They work together or not at all.
That definitely looks like MBD. Unfortunately his bones may be softening. By the looks of it he may have a spine deformation from the condition as well. How long has he looked like that? Get him on a more varied diet because lettuce and radicchio just doesn't provide enough nutrients. I don't know what you are using but you should re-evaluate temps, lighting, calcium, etc. If he does have MBD it can be cured!