Question
My koi pond recently had an unfriendly visit by a heron.  Just as the heron had extracted my largest frog with his poor legs hanging out of it's mouth I ran outside to scare it off.  I found my very large koi by the side of the pond slightly dried out in the sun yet still gasping for breaths.  I noticed a puncture wound at the top of his neck area and some bleeding from one gill.  I put him in the pond right away and tried stimulating him.  I thought for sure he would die quickly but two days later now in my basement in a child's swimming pool he rests lying on it's side near an aerator moving his eyes and both gills appear to be functioning.  What should I do now?

Answer
I'm sorry about the heron visit.  We have herons come to our pond too.  My page on herons is at http://www.fishpondinfo.com/birds/heron.htm
Herons will spear the fish.  Sometimes they can't swallow them, and just leave the poor fish to die by the pond.  I've had a few fish speared before.  If it's minor, the fish can recover.  Since he's made it two days, that's a good sign.

I would treat him with 0.1% pond salt, MelaFix, and some antibiotics like erythromycin to help prevent infection.  Aside from that and providing clean water with good filtration and aeration, there's not much you can do but wait and hope he makes it.  There is also a topical medication you can apply right to the wound called Bio-Bandage.  Here's a link to one source:

http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=12103&Ntt=bio%2Dba...

For general koi health, check out http://www.koivet.com if you haven't been there before.

Good luck!