Ok so let's just say hypothetically this fish does miraculously heal.
THEN WHAT???
The tank is too small. Like mentioned before, it will need 500+ gallons. The OP mentions that he lives in an area so incredibly remote that he is unable to get the proper medications. Where is he going to get a tank set up that size? If he lives in such a remote area, how will he even find someone to eventually adopt a fish that size?
I think that if this fish does ever heal, it will either get re-injured or become very ill due to the cramped quarters and aggressive tankmates (sooner rather than later). Then this WHOLE PROCESS of SUFFERING gets started all over again.
I think that this fish should be euthanized, because I do not see a bright future ahead of it, even if it does survive this terrible injury.
Clove oil can be purchased on the internet, fyi.
kj, this is a tough one. The argument you make here is solid; remote location and little possibility to ever make a tank that size a reality. I have to wonder, how did you come across this fish in the first place? As I said earlier in this thread, IMHO paroons should not be sold to the general public without certain clear demonstrations.
Damo, do you have any idea how old this catfish is? When and where did you get him?
Regardless, I have a personal story on this one. I care for an irridescent shark (pangasius catfish). These guys don't get as monstrously huge as the paroons, but they still need 400-500 gallons to be truly happy. I know the specimen was wild caught and likely ~5 years old at time of purchase. My wife (long before I met her) cared for this fish and he sadly spent nearly ten years in a 55 gallon tank; utterly tragic.
The result? When I came to care for him I could tell he was clearly stunted, had finrot, and had developed significant cataracts (a common affliction for this species likely accelerated by the poor conditions). He now lives in my 125 gallon Asian biotope and his health has improved dramatically. Still, he will (sadly) never get any bigger; the damage is done. His swollen, cataract filled eyes also make him unattractive for a potential customer if he was to be rehomed. This is one of those cases when you really are in the best situation to care for the specimen. The situation still stinks, but the best possible palliative care if provided. They usually live ~20-30 years in captivity so I know one day soon, I'll find he has passed. I will take comfort knowing that he had the best possible existence in his last days.
As for this paroon, if he continues his recovery, he's probably going to have massive scarring. No fish store will accept him for rehome thinking he can be sold (but may, perhaps, out of pity). This paroon has shown unbelievable resilience and is a fighter.... I don't beleive he deserves to be put down.
I do believe it is now damo's responsibility to make the best out of a bad situation and find a way to get him into the largest tank possible for a permanent home. That might mean getting online and finding someone "locally" with a tank that is suitable, or minimally, buying and setting up a 150 - 250 gallon tank to at least improve this lousy situation. It's going to be really tough....
Damo, under no circumstances can you return him to the original tank and expect him to do anything other than suffer greatly. I think this is the core of what kj is saying and I agree with him/her.
DV