Sick pleco, do not know what is going on

[festaedan]

Hello fello fishkeepers
I noticed a troubling ailment on my l114 yesterday while I was doing a water change. Her fins had been a little ripped up, but i assumed she just got in a fight with another fish. This rip turned into almost her entire dorsal fin melting away along with the skin behind it and some of her tail fin. Admittedly, I had not been able to check on the fish as carefully as I usually like to during the past week. Water parameters are almost perfect (tiny amount of nitrate). The tank is a standard 3 foot wide 300 gallon with three fx6s and a 60 gallon sump. The tankmates are 3 red hook silver dollars, 5 thin bar silver dollars, a breeding pair of chocolate cichlids, two adult pearsi cichlids, a black shark labeo, a foot long giraffe catfish, and 10 or so plecos, mostly small to medium pseudas except an 8" l27 and a 15" l160. None of the other plecos have had this issue. No new fish have been added in the past 9 months and most of the fish have been in this tank for well over a year. All fish, including the sick pleco, are eating well and normally. Any help would be appreciated. Below I have attached photos.
Thanks
-Dan

 

[BIG-G]

Looking at this and thinking through the possible causes I don’t think this was caused by the other fish.
Typically if the l114 had been into it with the other plecos you would see damage around the pectoral fins.
You should also see something going on with the other plecos .
If it were any of the cichlid I would think this would be something that you would notice while it was actually happening not at night or inside a hide or anything.
Is it possible that this is a burn from your heater?
It looks like it could also be fungal?
If it looks to be healing I would let it be.
But if it looks like this is still active necrosis I would remove and treat separately.
It’s also possible that the damage was a hit and run by one of the cichlids I guess, have you seen any aggressive behavior from any?

 

[festaedan]

Looking at this and thinking through the possible causes I don’t think this was caused by the other fish.
Typically if the l114 had been into it with the other plecos you would see damage around the pectoral fins.
You should also see something going on with the other plecos .
If it were any of the cichlid I would think this would be something that you would notice while it was actually happening not at night or inside a hide or anything.
Is it possible that this is a burn from your heater?
It looks like it could also be fungal?
If it looks to be healing I would let it be.
But if it looks like this is still active necrosis I would remove and treat separately.
It’s also possible that the damage was a hit and run by one of the cichlids I guess, have you seen any aggressive behavior from any?

The heaters are all in the sump and the infection/disease/necrosis seems to be getting worse. Once removed, what would be a good way to medicate?
Thank you for the quick response btw

 

[kno4te]

The heaters are all in the sump and the infection/disease/necrosis seems to be getting worse. Once removed, what would be a good way to medicate?
Thank you for the quick response btw

I’d separate and provide clean water and salt. 1 tsp per g. Monitor and if worsens then consider meds. Since getting worse I’d try some kanamycin and furan2 combo or triple sulfa. Let it heal up and reintroduce.

 

[BIG-G]

The heaters are all in the sump and the infection/disease/necrosis seems to be getting worse. Once removed, what would be a good way to medicate?
Thank you for the quick response btw

You are welcome.
I would follow the directions given by kno4te
Good luck