Hi,
One point worth considering.
We tend to use these terms like "mouth rot", "R.I." and "scale rot" as though they are specific conditions always caused by the same bacteria/ fungus/ virus etc.
But, in reality, they are just umbrella terms for multiple conditions with multiple specific causes and behaviours. That is why taking that extra step in getting a culture done before treatment starts can make such a difference to the medication ultimately used and thus (hopefully ) the speed of recovery etc.
dr del