Reviving fish from the "Death Roll"

[Barracuda]

My new angelfish is performing the "death roll" - the one when they seem too weak to do anything, and start rolling around in the water, occasionally getting sucked up near the filter intake and getting pushed out from the filter output.

The fish is a new one i bought recently (last week), it is currently in quarantine. In fact i bought 2 at the same time, but one died the night after i brought it home. Acclimatised properly, tank cycled and everything. No surface/physical problems, probably a disease, something internal they picked up from the fish shop...not very healthy. In fact there were a few dead/looking fish in a few other tanks, since they had so many of this fish (really nice long-finned veiltail) in heaps of tanks, i spotted the least populated tank with the most active/colourful fish in there, which happened to be right at the top needing a ladder to get to. I would have thought these were the healthiest of the lot, as the others were already showing physical problems such as fin rot/chews, swimming problems etc...Never buying from there again...

So is there a way of reviving them? Or is it pretty much on its last legs and gonna die any minute now?

Thanks

[Hollowman]

I would do it a favour and cull it humanly.

I would have run a mile just seeing other ill fish in the shop. Lesson to learn I'm afraid.
Sorry

[Robdog]

I would pop it in a plastic bag and shove it in the freezer with the aim of reviving it when they find the cure to "scabby fish shop disease".

[taksan]

I've got one thats been doing that off and on for a couple of YEARS ....
Seems to come and go ...

[Andrew Soh]

Is it dead yet?

If not, makewater change and add salt @200gms per 100 litres of water. That may save it but no guarantee as the fish might be chronically infected and infested by organisms.

Take care,
Andrew