Iridovirus?

[Betta splendens]

Ok my Dwarf gourami is doing bad. I think it's Iridovirus, because he's weak, loss of apeetite, and he's kinda bulged more on one side of his body. His lower scales are a more darker, vivid blue than they were before.

This is a spitting immage of what killed my beloved golden gourami, my first acual fish.

If this IS Iridovirus, I know he's going to die. ='(

But I want to know what caused it. Please for the sake of my other fish.


-betta splendens

 

[WILDER]

How many gallons or litres is the tank.
How many fish and which type.
Water stats in ammonia,nitrite,nitrate,and ph.
The bulge does it look hard or like filled with fluid.