Koi attacked by heron--broken back?

[Booknerd1223]

Three years ago I bought a home and inherited a pond with 11 beautiful koi. We've had no issues until this past Tuesday when I went in the backyard only to see a large heron devouring my koi. I was devastated! I was able to scare him off before he took them all. I have at least three left in the pond, but two of my larger guys were injured, one on the ground. I found the other (named October) floating in the pond on his side. I thought he was dead at first, but when I went to collect him to bury him, he started moving. I have secured the pond against future attacks and I've isolated my two injured koi into separate tubs in my garage, each with a bubbler. My koi that was on the ground (his name is May) was unresponsive at first, but has since rebounded quite strongly and is swimming--albeit slowly--in his tub. He was scraped up a bit and had scales pulled off, but no open wounds that I can tell. He has retained his color. If he continues to do well, I plan to return him to the pond this weekend after I install permanent protections against the heron.

My other koi, October, has not gotten any worse, but is still on his side. It looks as if his back was broken? His body is curved and I don't think he can upright himself. He is still very responsive to sound and visual stimuli--he wags his fins when he sees me or when I speak to him. He can also move his tail and has managed to swim backwards in his tub, still on his side. He does not appear to have any surface wounds, though I haven't looked on his downward facing side yet. I admittedly do not know very much about these magnificent creatures--the previous owner showed me how to provide them basic care and keep the pond cleaned and the pump going, but that's the extent of my knowledge. I am absolutely sick about this and I feel terrible for all of them. I still have six unaccounted for, but I'm sure they're simply just gone. Never thought I could get attached to fish, but these guys were special--and I feel like I let them down.

I'm at a loss for what I should do, if anything, to help October. I'm afraid to touch him for fear of hurting him more, and I haven't been able to find any answers yet. I'm hoping someone on this forum can help me determine what to do. Again, he hasn't lost any color and is still very responsive. I will try to attach a photo from when I first found him.

[koi4u2c]

Check the ammonia and nitrite levels in your tubs. The ammonia can rise quite rapidly and kill the fish.

[RichToyBox]

Heron often spear the fish near the back bone. For larger fish that they cannot eat, they want them out of the way from providing cover for smaller fish, and if they can eat them, having them immobilized makes it easier. Pick the fish up turning right side up and look for a wound near the back. The chances of recovery are slim, and the most humane thing to do is to put the fish down. Sorry.

[Cape Fear Koi]

I had one spear a fish and bruise it’s back. The bruise healed in about 5 AH’s but the it’s back was permanently disfigured and swam in circles. After about 10 days the injury never corrected itself and I had to do I didn’t want to.
Hope yours gets better.

[Booknerd1223]

Thank you for this information! I bought ammonia test strips. So far, the water is at the safe level but I will monitor it.

[Booknerd1223]

Heron often spear the fish near the back bone. For larger fish that they cannot eat, they want them out of the way from providing cover for smaller fish, and if they can eat them, having them immobilized makes it easier. Pick the fish up turning right side up and look for a wound near the back. The chances of recovery are slim, and the most humane thing to do is to put the fish down. Sorry.

Richard,

I checked his back and you are correct--there's a very small place close to the backbone where it appears he was injured. He was not bleeding when I found him, so I'm not sure how deep the wound is. It does not appear to be a hole, per se--at least not a gaping hole. When I held him and tried to right him, he started trying to swim. He still has full use of his fins and tail--I can feel his muscles contracting as he moves. When I let him go, he tries to stay upright but then rolls back on the same side. I tried turning him over to the other side to see what would happen. He went upside down, then back to his original position. Is it possible that his swim bladder is injured? If so, does this heal? His color is still very good, and he is still very responsive.

Thanks all for any and all information/suggestions.