BCI Muscle Loss

[GFLY]

Hi guys, my 9 month old Boa has had a lot of muscle loss over the past few weeks... I took her to the vet and had a fecal and blood test, but nothing came up that was out of the ordinary. She is eating just fine, but I've noticed loose skin and that her spine is more visible than it should be. I also have noticed that she feels pretty squishy and not like a lean piece of meat. Starting to subtly feel her ribs when handling as well when I was checking for lumps (if any). Any thoughts/ideas as to what can cause muscle loss in infant boas? I'm at a loss here since I literally can't find anything online about muscle loss in Boas.