I have a gold fish with a diseases that...

[farhad_1971]

...create a bloody hole under it's eye .what shall I do ?

[em88_dude]

that doesnt sound good at all. id go to the vet, or somewhere that specialises in auqatic life and ask for advice. it may well be that u can get something to add to the water in the tank, that will kill off an bacteria thats causing this problem with your fish.hope everything goes ok.

[magicgee]

Flush that fish down the toliet and get a new one.

[balle212]

flush it and buy a new one

[Tucker]

put it out of its misery... im sorry for you...

[bluishwolf]

Go to a pet store that sells goldfish and ask them, or ask a veterinarian. Don't do the cruel thing some clowns who answered your question suggested: to flush it down. That would be cruel.

[cellerdor]

Put melafix in the tank, it is an antibacterial that will help prevent infection from the injury. I've never heard of a disease like this, though hole-in-the-head disease sounds similar. Are there any other fish in the tank that could have hurt the fish?

en.wikipedia.org (http://en.wikipedia.org/wiki/Hole_in_the_head_disease)

[PSOs gal]

Go to your local fish store and get some medication for your fish. Treat it as directed.