redearslider.com

Something is wrong with my red ear slider’s tail. Its discolored. Yellowish and markings faded, and there is a few pieces missing. He is basking a bit more in the last few days. The very tip has the correct coloring, for reference in the photos.

I'm not sure what this could be, though it looks very serious. There are some skin fungus infections that have a white appearance but I would also be worried if this were infected tissue. I recommend you take him to vet ASAP.