He has big sores on his body that aren't healing. I thought he may have furnunculosis and treated him with Tank Buddies Fungus Clear, but it's not helping. He hasn't eaten in days and he appears to be gasping. His stomach is bulging out and he's swimming with clamped fins and just appears to be in misery. I can't take seeing him like this. I'm worried that he may have tuberculosis.
Any ideas? If I need to euthanize him, what is the best way? I've read something about putting him in the freezer and letting him freeze to death. That just seems cruel, but I would like to do a fishy autopsy if I need to put him under.