Cory Catfish possibe problem

Question
Hi The barbels on several of my catfish have become white and look swollen. I thought it was their age as they are over 10 years old but now one of my youngsters that I bred has also developed these. Fish are freshwater on a thin fine sand floor(no pebbles) Ive only had 2 catfish die in 12 years so I must be looking after them ok. They are in a big tank . Have you any idea what this might be. Their fins are ok.
Thankyou
Penny

Answer
Penny,
without actually seeing the fish in real time its difficult to diagnose the issue.
Have you checked the PH? temp,hardness etc...just to be on the safe side.
The fact that you have had these fish for so long and have bred them leads me believe that
the conditions are fine.
That said, some pebbles would not be a bad thing, the smooth river stones would be perfect as the corys like that and the smooth won;t injure their barbels.
Do the fish have a "rough" appearance to them?
If so a treatment with a general type cure, Clout may help.
the addition of a small amount of salt to the water will also not hurt.
2tsp per gal...
I am sorry I cannot be more specific but I would have to actually see the fish.
Good Luck and congrats on breeding the cats..