Hello and welcome. My name is ***** ***** I'm a biologist with a special interest in reptiles. I'm sorry to hear of this incident.
I know you would like to have a home remedy, and I would love to give you one, but when it comes to shell injuries, there simply isn't one. This sounds like a particularly extensive injury. Michaelengelo has the best chance of healing if you take him to a vet. The shell is actually living tissue, part of the turtle's skeleton. Cracks and breaks in the shell are very prone to infection. Such infections become life-threatening. I'll give you a first aid measure in a moment, but I strongly recommend making an appointment with a reptile vet as soon as possible. These links will take you to directories of such vets:
Now for first aid. Get some Betadine, which is sold in the first aid departments of discount stores and pharmacies. Pour some into the wounds in the shell to kill bacteria. Let the Betadine dry before putting him back in his tank. This should be repeated twice per day until you can get to the vet. If you choose to keep him in a dry area, be sure to give him two 30 minute soaks each day to prevent dehydration.
You'll also want to be sure that he has adequate calcium and UVB light so his body can repair the bone in the shell. If you don't already have one, put a cuttlebone (sold in the bird departments of pet stores) in the tank to provide calcium. Make sure you have a UVB bulb less than 6 months old that has an output of 10%. I recommend the Reptisun 10.0 in the straight tube style. It should be on 12 to 14 hours per day.
If you have more questions, let me know by clicking on REPLY. I hope Michaelengelo will reach a full recovery.
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