koi with extended stomach

Question
I have a 1000 gallon pond in the yard with fish that are 13 years old- the fish
with the extended stomach is about 5 years old- its a fantail koi- looks like a
goldfish with a huge wonderful tail- over the winter I noticed its belly gettin
large- simply thought it was pregnant anf illed with eggs- now spring has
spung and it has gotten even larger- I took a photo with my phone if you
need it-looks like he swallowed a baseball- no kiddin

Answer
Hi Ed:  Thanks for the question.  I am really not a koi expert.  I know a few things about them but don't really feel like I will do you  justice with this issue.  But... here is what I can tell you.  Karen Fields or Chris Robbins are two experts here that I would ask this question of.  In the meantime...  koi can get intestinal blockages after being dormant in the winter.  There is also a disease called Dropsy that makes fish look like they are bloated.  you can do a google search for koi and dropsy and see the pictures... it is a very distinctive looking disease... where the scales stand out from the body.  dave