My 4 year-old male, yellow belly slider turtle has red markings on his shell in certain areas of his neck. Namely, under the neck skin, and shell. It also is appearing in the back of his legs, and under his tail on the shell and in some parts of his skin. He also appears lethargic, but has a healthy appetite. His tank is at optimal temperatures and humidity and he has a healthy basking schedule.
I can’t afford veterinary services at this time, so I’d like to know first what this is, and if there’s anything I can do to treat it at home.