Mature angelfish sick- possibly dropsy?

[elliott_001]

Hi all, came home today to find my largest (and most dominant) of 4 angels looking unwell.

Only visible symptoms I can see are a slightly swollen belly and staying close to the surface.

He doesn't react like he normally does when I go near the tank and wouldn't eat when I fed them.

I'll be gutted to loose this fish.
I do not have a qt tank. Have some Epsom salts, but not a great deal. I have a few bottles of different treatments, one of which is anti internal bacteria by interpet.

Tanks established, balanced and stable, all other fish are perfectly fine.

Slight chance he could have over eaten, but probably not.

Any suggestions would be great.
Thanks,
Dave

 

[elliott_001]

Update, angel is not staying at surface, has moved around the tank a bit- generally hiding but then every now and the suddenly darts about, almost like 'flashing' but not. He's clearly distressed and uncomfortable

 

[elliott_001]

Well, I'm gutted.

The angel has just died. It was really bizarre. He would swim at the surface and dart around, then sit quiet for a bit. He ended up suddenly darting around the tank out of control- his head and then Sat stunned and died!

Appearance;
On closer inspection one of his eyes look a tad milky and possibly bulging.

Stomach possibly a bit bloated but other than that was normal.

Behaviour was fine until today.

Weekly water change was 3 days ago.

Any suggestions?