Fancy Goldfish Has fallen over?

[strider]

Hi all
I have a fancy goldfish, it must be getting on 12 or 13 years old now, but it has fallen over!, basically it lies on its side on the substrate, it looks healthy, clear eyes etc, pretty sure its still feeding too, but just lies in a corner on its side, have tried to move it so it is upright, it will sit there for a while before swimming away, but as soon as it moves it falls over again.
Can i help it in any way, is this common? or is it time to face facts and help the little fella on his way, please help :-(

 

[charliebankston]

I haven't kept gold fish in over 30 years, so I'm def no expert. You might read up on swim bladder disease in gold fish and also what the life span normally is

 

[Autumnsky]

Are you doing regular water changes? Sometimes the build up of TDS can have an effect.

What size if the tank and what is the filtration?

Have you ever fed green garden peas for alleviating constipation?

Try peas and therapy treatment of Epsom salts.

Also here is the ES treatment.
https://www.aquariumadvice.com/forums/f17/using-epsom-salt-in-fish-therapy-374191.html

Do you ever use any aquarium salt? Sometimes the additions of some salt can help with osmotic regulation osmoregulation. You can start with a rounded teaspoon for every gallon, make sure it doesn't have additives and no iodine! Sea salt and kosher salt no additives can also work.

https://en.wikipedia.org/wiki/Osmor...active regulation,case is represented by body