Is there a cure for the TB? If not, is there a humane way to put the fish to sleep?
The cure for TB is typically more than most will go to, it is a long process and most recommend destroying the fish (since TB is contagious to your other fish and yourself). The most humane method I am aware of is to put the fish in an ICE
cold bucket of water. The shock to the fishes system will kill it very quickly and it is said the fish doesn't feel it.