Cranky Eater getting Sick

[Dracorex5]

Ive had my normal ball python for nearly five years now. He is a very important snake, as he is a stress reducer animal. But lately he's been doing more harm than help, mostly to himself. He's always been an incredibly picky eater. As a baby he wouldnt touch frozen, no matter what tricks we used. We had to resort to live after over a month of him not feeding as a hatchling. He is still a mess when it comes to eating but its getting much more severe. He's large eneogh for medium rats, but refuses anything thats not a live mouse. This wouldnt to a horrid issue, just obnoxious, if he would eat more than one or two mice at a time. Even if i space the feedings out over days, he wont eat a mouse today and one tomorrow. He constantly refuses food, likely because he's not hungry at THAT monent. Ive tried different foods and tricks to try and tempt him but he eats when he likes. He's been losing weight steadily over the passed few months. I had him tested and he doesnt have parasites of any sort or anythig. He just wont eat eneogh! He is the skinniest pampered ball python in the world, and he's finally dropped below a healthy weight for a snake his size. What should i do? Im not sure if he's suffering something i cant see, or is just rowdy and picky. Are my worries justified? Thanks!

[Wapadi]

Have you tried asf s?

[PitOnTheProwl]

pics and what is his weight?
I have two males that are over 1000g that are mousers

[kitedemon]

How are his temps especially ambient air temps. They seem to make a big difference sometimes and get over looked.

[Dracorex5]

He has a warm side of 85-90 depending on the time of day and a cool side of about 75. He happily slithers between the two. He hasnt slowed down activity wise with the winter or with his failing appetite. He has a very large cage and makes a little too much use of it. I have tried ASFs, gerbils, rats, mice, even a quail and he still wont eat anything but a mouse or two a week. He's only about 2.6 feet long but his weight is about 900. He was at 1060 in may, he just looks sooo skinny... Ill try to post some pics of him tonight. He just used to eat so much more before april.