Will my python ever recover?

[Bogertophis]

Yes, she has not been in contact with another python her entire life, nor have I handled another python her entire life. I never been to a reptile event either. However, she did get mites when she was 1 year old. I was able to get rid of them pretty quickly though. With this being said, can IBD and nidovirus be ruled out?

I did make a big branch like structure out of pvc pipe a few years ago. Although, she never used it. I think your missing the point. Her activity level and muscle mass were both fine last year with the same exact furnishings. Again, this all started when I noticed the blood from her mouth back in October of last year. For example, she is just as inactive outside of her enclosure. I take her in my bedroom with plenty of things to climb on but she just wants to find a spot to coil up and rest.

Furthermore, if she is eating larger rodents with less activity, she should be gaining weight not losing weight. I know the rats aren't that much larger and she hasn't lost that much weight, but still.
After pulling her out tonight, I know something is very wrong, I really think she is dying.

You say you had no contact with another python, but what about any other kinds of snakes? Others can transmit diseases too, & I wonder how she got mites as a yearling if you & she had no contact with other snakes?

I would think that IBD is very unlikely, since pythons generally succumb very quickly, unlike some other snakes that can carry it without symptoms.

What did you use to treat for mites? (What I'm really getting at are possible chemical exposures that may have caused nerve damage etc.?)

Assuming snakes are at least a tiny bit like humans, waiting until you're way up in years to suddenly try to get in shape (build muscle mass & tone) is all wrong- aging makes one lose quite a bit, especially if no effort is made to counteract the loss. Maybe that's why you're "suddenly" seeing a change that was simply too subtle to notice before.

As for the very minor weight loss- it's probably the difference made by one defecation, or perhaps her digestion isn't what it used to be either.

It's not necessarily just one thing causing the changes you describe- it could be 3 or 4. Anyway, I've brainstormed & speculated all I can- it's really in the hands of your vet, who is actually seeing your snake, & whose training & experience is essential. I've kept many snakes, & for decades- in my experience, snakes that are "dying" just do not have a good appetite.