Red spots on my diamond goby, please help!

[gobble]

I noticed yesterday that my diamond goby wasn't himself. Today I noticed him hidden and he wouldn't come out and eat. I caught him and put 5 gallons of tank water into 5 gallons of matching salinity and temperature into a hospital tank, for 10 gallons total. I just dosed metroplex, kanaplex and furan-2 and added an air stone.

Does this look like an infection from something? Only thing new in my tank is I dosed Prazipro 2 days ago.

Anything else I should do?

 

[HotRocks]

It looks like an infection or aggression damage. Any aggression observed? I would continue with your treatment for 10-14 days.

 

[gobble]

No fish currently in the tank that would be aggressive to this guy. He's one of the largest fish in the tank.