Male Platy fish has swollen belly? pictures included.

I have had this male since it was born and it has always looked slightly pointed in the belly, until recently the belly has really pointed and swollen. Someone has said it looks like a tumour, or maybe dropsy. I have been told to euthanise it by another site. Can someone help me identify whats wrong with him?
He swims fine, eats his food and seems like a happy enough fish.
These are pictures before i transferred him to his hospital tank.

The fish has a few genetic defects (top part of the body and head) that is was presumably born with. The belly could be an exaggeration of these defects or something growing in him. However, if he is eating and you like him then just let him be.
If he stops feeding, or his scales stick out, or he starts bleeding or body parts start poking out of the skin, then put him down.

Colin_T said:

The fish has a few genetic defects (top part of the body and head) that is was presumably born with. The belly could be an exaggeration of these defects or something growing in him. However, if he is eating and you like him then just let him be.
If he stops feeding, or his scales stick out, or he starts bleeding or body parts start poking out of the skin, then put him down.

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That does make sense, he came from a tank of males and females that were related and it might be due to inbreeding. Thanks for the advice, do you think it is safe to put him back into his old tank with other platys?

the fish was not fed a good quality diet and/or was kept in sub par water conditions at birth, my guess is water conditions,

this is why its so important to feed fry good food and keep a constant eye on water conditions,

its also a reason why many fry are culled not long after born,

if it was my fish, i would put him down because he is probably suffering......but then again, i would have put him down long ago

mikey11 said:

the fish was not fed a good quality diet and/or was kept in sub par water conditions at birth, my guess is water conditions,

this is why its so important to feed fry good food and keep a constant eye on water conditions,

its also a reason why many fry are culled not long after born

Click to expand...

What about its brothers and sisters who were brought up in the same water and fed the same food? although i could see it being underfed as a lot of the time fry swam to the back of the tank in compartment and got stuck, where food doesnt get to.

I think it is fine for him to go back into his normal tank. I don't think the stomach/ belly issue is something that will spread to the other fishes.

Just monitor him and if he stops feeding then put him down, but while he is swimming about and eating normally, let him be