Platy passed away really bloated

[Pennyangus]

Hi noticed a platy on the floor of the tank heavy breathing yesterday and found it dead today its super swollen and bloated any know what causes this so I can look out for it in my other fish

 

[vince82]

difficult to say after the fish is dead, but bloated dead fish usually is dropsy. Monitor all the other fish, any lifted scale means IMMEDIATE isolation. I have never personally seen a fish recover from dropsy, but some people have had success with methylene blue.