if I don't treat this colony, I may have the issue spreading to my other colonies, that would be irresponsible.
As is not knowing what is the correct diagnosis surely.
Send a sample to NBU. bee inspector visit.
I too, will give you a quote:
Diagnosis
Nosema diagnosis can be carried out using a microscope with X 400 magnification. Collect about 30 bees and mash the abdomens in a pestle and mortar with a few drops of water. Deliver a single drop of the resulting soup onto a microscope slide and put on a cover. Under the microscope look for little pale rice shaped grains that are Nosema spores. There is little difference to be seen between N. apis and N. ceranae spores, if you need to know send a sample to the NBU for analysis.
From
http://www.bee-craft.com/beekeeping-information/expert-beekeeping/nosema-disease/
I seem to remember that you passed your basic. Where you took your course must surely have microscopes. If not, pretty poor, leave and find association that has.
My association is having everybody bring in 30 bees at end of summer to discover nosema - a
simple procedure.
Be responsible and don't treat without knowing what you are treating.
These creatures have enough rubbish poured over them without adding to their angst, the likelihood of resistance, 'I think it
could be this so I'll dose them'.
As said read more and look on here before afflicting your bees with possible incorrect treatments.
The bees rely on YOU and are powerless to avoid what you do to them.
There are always a thousand reasons why not and only one why.
By the way, the nosema testing at our association is being done by a young lad of 11.
it is a very productive colony 
