Losing Fish - Photo Of Problem

[jasmas]

Lost a few fish over the last week to two, got another post where I've had good advice waiting on medication from overseas.
 
Today lost another who was in our hospital tank. This yellow lab had a small hole type thing start to show on it's side, which has now darkened in colour.
 
Unfortunately it didn't survive more than a few days. Here is a photo of the problem, can anyone confirm the disease, probable cause & cure.
 
Thanks

 

[AmtotheBurr]

I'm sorry about the fish loss. I know this forum has tons of knowledgeable folks so I hope you get this answered soon. Good luck!

 

[nic1]

Hi, I'm not 100% but this to me looks like an ulcer, its the result of a bacterial infection.
What meds did you order?

 

[jasmas]

Fishzole - Metronidazole. 
 
I have another thread - moved 4 to hospital tank and started treatment this morning. Fingers crossed.