My goldfish has gotten fat over the past few weeks very quickly and i cant tell if it has a disease, bloating or is pregnant. Its been going on for at least 2 months. She is a comet goldfish so the belly shows. Her scales are not puffy and she does not have symptoms like dropsy. She is swimming fine and does not show any trouble. However, there is a red spot somewhere near the bottom of her stomach. I cant really tell the gender so im assuming its a girl. She doesnt have the bumps near the gills that would show if she was pregnant. In the tank there is only one other comet goldfish which is doing fine. They usually like to chase each other around and rub against each other affectionately. They have been living together for more than 6 years. If you know the cause that’d be great 
