I have a fish pond and it has 4 gold fish that I bought from the pet store. Well one of them is getting really fat. The others are doing great. I went out and tried to feed it but it wouldn't eat. The other ate fine. What could be wrong with it. I thought it might be pregnant but I have read other fish questions and they say it is impossible. So what could be wrong with it. Remember the other 3 are doing great. I have had them in there for a little over a year. I cut back on feeding them over a week ago and I also give them some Cheerios in the evenings.