I have a 2000 gal outdoor, above-ground tank with about 10 Koi. I've had these 10 fish for ~7 years with no problems. They probably weigh about 5 pounds each. Last fall a single Showa stopped eating. No other symptoms. Usually stayed at the bottom of the pond but was somewhat active. All other fish normal. As it went into winter the situation remained and the fish were not fed through the winter. I have started feeding again now in early April. A complete water change about 14 days ago. All fish eating as usual and remain fine except the same Showa, which has the same symptoms. It's abdomen may be extended, I'm about to net and take a closer look. Could it be egg bound? If so is there any home remedy? What are the other possibilities. I'm a new member and no expert, but I do have many years experience with this group of fish. Since the condition remained the same over winter it seems strange that only this one fish has symptoms. Pond always has clean water with heavy biological filtration. Thanks for any help. I did read some info on your forum in regard to egg blockage and was not encouraged by the treatments discussed.