TL/DR: My ball python has had an RI for months and hasn't cleared up despite antibiotics getting rid of the bacterial infection, what can I do to help her?


I recently got a 4 year old female ball python (about 6months ago) and a few weeks after we got her we noticed some mucus in her mouth. Fearing the worst me and my partner took her to the vet and they confirmed it was a respiratory infection and we started with antibiotics (injections) and sent a swab off to the lab to be analysed. When the results came back they identified two types of bacteria, one of which was resistant to the type of antibiotic we were using so we switched to one that would be effective on both. After a few weeks of these injections the RI hadn't cleared up at all so we switched to another antibiotic again, that should be effective against both bacteria.


After a few more weeks of this she seemed to clear up a little bit but there was still mucus and some slight wheezing/popping. We took her back to the vets and took another swab, this time looking for bacterial and fungal infections. While we were waiting for the lab results to come back (5 days) we also started nebulizing her daily with a solution from the vets, saline with some antiseptic dissolved into it.


The results came back clear, no bacterial or fungal infections it there was still mucus so we continued to nebulize her assuming it was just leftover mucus taking a long time to fully clear up. Well that was about a month ago but she still is mucousy and we've stopped nebulizing her as we didn't notice it making that much of a difference and thought the daily disturbance might be stressing her out (although she seemed fine once she was in the box we nebulised her in).


Throughout this time she hasn't eaten (we have offered her food but she hasn't taken any of it) and has had one successful shed (although there was a very small spot of blood on her paper substrate after, the skin came off all in one long piece) and is about to have another shed (currently milky). She hasnt really lost any weight (was 1.41kg with the first vet visit, hadnt lost any weight a couple months later and although we havent weighed her since she seems about the same weight).


Husbandry:
We're keeping her in a wooden vivarium with newspaper substrate, she has a warm hide under a ceramic heat lamp (no light and covered by a cage) and a cool hide further down the Viv. The hot end of the Viv is about 31/32°C (88°F) and the ambient temp is about 27/28°C (81°F) in the day. During the summer we turned the lamp off at night but it's getting colder where we live so we just turn the lamp down so the hot end is about 26°C (78°F) and the ambient temp is about 22°C (72°F). We keep the humidity between 50/60% and all temps are recorded with a temp gun and a digital hygrometer to measure the ambient temp and humidity inside the viv.


Also whenever we do handle her she seems nice and relaxed, exploratory but not running away, not tense and nice and loose. Although we've kept handling to a minimum for the last few months.


All of the treatments were as instructed from the vet but we're just wondering if anyone could share any advice on how we can do ally cure the RI/insights as to why it hasn't cleared up by now?

P.S. just phoned the RSPCA reptile rescue to see if they had any advice and suggested changing the substrate to help increase the humidity and to get a UV bulb, I was under the impresion UV bulbs were pretty unnecessary as BPs are nocturnal and spend all day in their hides.