side swimming koi

Question
koiWe have a new pond and purchased two koi and one Catfish.  The white butterfly koi inches.  Disappeared for a week (hiding)  Finally we found it and took it out of the pond.,  It looks Leatherette and is side swimming erratically or laying on it's side head in an upward direction.  We also had purchased four shubunkin.  All is well. Ph, temp, amonnia and all within normal limits.  Have been adding melafix to water since fish have arrived.  We have a UV filter, waterfall etc.  Please advise.  I don't want the fish to suffer of course would prefer to save. Thanks and advice would be greatly appreciated.

Answer
Hi,
It could be swim bladder problems if you can take it out of the pond and put it in a quarantine tank and gradualy heat the water to 70 degrees fahrenhite   and add cooking salt( not domestic table salt as this contains chemicals) at 1 to 3 grams per litre of water in case of parasites it may help to save it but with not seeing the fish there is not much else that I can say, best of luck.
George.