Question
I just recently started having goldfish as pets and am not quite sure what is happening with one of my goldfish that I just got. I am not sure whether my goldfish is breeding or whether it is sick. At first I thought that maybe she was breeding, but now I am not so sure. She is probably only about two or three inches long. Underneath the fish is swollen and there is a thin white string that is attached to her that is coming out of her hole. She also hasn't been eating a lot. If you could help me out here it would be great. Thanks so much.

Answer
At 2-3" long, she/he is too small to breed yet.  How big is the swelling?  If it's severe, it may be a bacterial infection.  What "hole" is the white string coming from?  If it's from the wound, that makes sense.  A thin white string hanging off a fish is normally the egg sacks of an anchor worm.  Your goldfish may have anchor worm.  Look it up on the internet.  I mention it on my site at http://www.fishpondinfo.com/health.htm
Luckily, with the right meds as my site and others say, it's easily treatable.  If the white string is coming from his/her vent/anus, it may just be feces.  Sick fish often have abnormal excrement.  This would go along with a bacterial infection that causes tumors.  Good luck!