Fungal infections can also affect the breathing and lead to a bacterial infection.....it does sound suspicious when you mention all this, and I do believe it could well be linked.
Elijah pig has just got over oral fungal. He became quiet and withdrawn very suddenly one day a month or so ago. Reluctant to eat as well; dental examination showed teeth fine, so treated for oral fungal. The turnaround happened within a couple of doses, I naively stopped dosing after one week instead of the standard three weeks....so it returned with a vengeance and he's not long finished the full three week course. His symptoms were quite simply dribbling saliva which smelt very stale, and a very faint and occasional click when breathing.
As he had the faint and occasional click when breathing, I dosed with children's Nurofen as well as Daktarin Oral Gel; I have not studied much into this but from what I have read, I believe it may be the respiratory inflammation caused by the fungal spores that can then predispose the pig to a bacterial infection. Logic said use an anti-inflammatory alongside the anti-fungal and the Nurofen did seem to do the trick. The dribbling took a while to clear, the end of week two of meds before that started to ease, but the click disappeared within a couple of days.