As I said in your thread in the "Health" section, this is caused by an injury like a burn or by fungus. If the tortoise were too dry, fungus would NOT be a problem.
I don't have any substrate in my adult sulcata's shed. He has a rubber mat and a pig blanket. When he goes outside, he goes out onto grass.
Wow that doesn't look good. You may want to take him to the vet. I would think what she said is right, that's probably from some sort of injury, as she mentioned a burn. Are your lights too close? Might need some medicine for your little guy!
To answer your question about pig blankets, basically heated mats
A pig blanket is a ridged plastic heating mat. Very heavy duty construction. These are designed for keeping piglets warm. Pigs are hard on things like this. You can look up Stanfield pig blanket on google for more complete information.
I had him checked for fungus and nothing was found? How far should his lights be away from him? And would I not need lights if I had a pig blanket? And thanks for all your replies guys an girls
I am in liverpool England, he is in an outside shed built for him, roughly 7ft long 2.5/3ft high heated with 100 watt bulbs and uv lights, he goes out on the garden when warm enough, he is ten years old and had this problem for a few months, he seem a vet a few months ago but to no avail, he has a hay substrate an is fed mainly grass with calcium occasionally and some Kayle, fruit and veg, please help our Dellboy
I will send some pics when I am home in 4hours also no I only monitor his sleeping area temp as scared of him freezing in our winter weather and also what is carapace temp?
Frequently when tortoises are housed outside, hot bulbs must be used to keep the temps up. As sulcatas grow and the tops of their shells (the carapace) get taller, they get too close to the hot bulbs and it can kill or burn the scute material or underlying tissue. I have a couple of rescues that had this happen to them, and I see it frequently. You need to know what the temperature of your tortoises top shell is when he's under the heat lamps. You might be burning him.
Here is one for a single male. In this one I used radiant heat panels over head and a heat mat on bottom all controlled by a thermostat hidden in the box on the wall there. The radiant heat panels give them warmth from over head, but they don't ever get hot enough to burn them.
I have added insulation and covered the walls in plywood since this photo. It stays nice and warm in there on below freezing nights now.
All of these heating strategies are designed to be both safe and efficient for a large sulcata. Hope it gives you some ideas.