The first thing you have to do is look after the fishes water properly. (The poison (ammonia) in the water is what has caused the fungus). The basic rules for keeping fish are:- 1 inch of fish needs a minimum of 1 gallon of water, all fish need a cycled filter running permanently and a fish tank should have at least 50% of its water changed every week. A goldfish grows to around 10 inches so it should be in a tank that holds at least 10 gallons of water (Nominally a 13 gallon tank or larger). You can get fungus cure at a pet ashop but it will do you no good at all if you don't follow the basics I have just given you and look after the fishes water properly.
The cause of fin rot is ammonia (poison) in the water. Adding chemicals will not help anything without a water change. My advice is to do a water change ASAP. If you follow the basic rules of fishkeeping the fish could get better if its gills have not been damaged too much by the ammonia. The rules of fishkeeping are . :- 1 inch of fish needs a MINIMUM of 1 gallon of water (better is 2 or 3 gallons per inch of fish). :- Every tank needs to have a cycled filter running permanently. (this removes ammonia biologically). :- Every tank needs at least 50% of its water replaced every week. (this removes excess nitrates). Keep to the above rules, and your fish stand a chance of survival. Fail to keep them, and I can guarantee you will have constant health problems with your fish.
My Advice is. Do a water change ASAP. There are simple, basic rules for successfully keeping fish. The rules are. :- 1 inch of fish needs at least 1 gallon of water. :- Every tank needs a permanently running cycled filter. :- Every tank needs at leadt 50% of its water replaced every week. Follow the rules and the fish will be OK. Fail to follow the rules and I can guarantee that your fish will be constantly getting sick and will live a shortened lifespan. Adding 1 teaspoonfull of aquarium/sea salt per gallon of water will help heal the fishes fungus. Stop adding salt once the fungus has gone and it will slowly be reduced as you do the weekly water changes.
If your goldfish has red patches, is losing its tail and has a fin clamped shut, this could mean that it is sick. You should take it to a vet if possible.
Having your goldfishes tail turn white could mean your goldfish is sick but it could also just be new tail growth.When goldfish grow new tail tissue it may appear white or grayish.This usually happens when a goldfish isn't fully grown .If it is new tail growth than it will be on the end and tips of the fish's tail not the whole tail.
stretch a normal gold fish tail
If you mean falling off then NO. But if you mean like the skin comes off, it happens occasionally and nothing is wrong.
The butterfly tail goldfish usually measures in at 6-7 inches. They are condsidered to be medium in size compared to other goldfish. Their closest relative, the fantail goldfish, is slightly smaller at about 4-6 inches in length.
The shape of a fishes tail is decided by its genetic makeup. There is no "treatment" for a bent tail.
My goldfish Fan tail is attacking my small gold fish, they have been together for over a month now but has only recently started to nibble at the smaller goldfish, how can i stop this
it has a short tail
it only has a small tail
when a goldfish puffs it puffs out what it was chewing on
because fish are cannibals
as long as the tail is removed first.