dropped tail/lethargic goldfish

Question
HI. My goldfish has had a dropped tail for about a day now and today he is very lethargic and isn't very interested in food. What's wrong?

Answer
Hi Gina;

What size tank?
How big is your fish?
How long has the tank been set up?
How often do you change water or clean his tank?
What kind of filter do you have?
Does the tank have a filter?

Let me know as soon as you can......

Chris Robbins