Fish Seems Unable To Eat

[LibraKoi]

Sadly you were unlucky with your koi but what I cant understand is how long had this been going on for it to get so thin ?
Do you know how to anethitize your fish so that in future you can check yourself for obstructions in your koi's mouths rather than pay vets bills .
I've had koi from time to time with obstructtions in their mouths and its a simple matter to anethatize your koi pop a pair of tweezers in its mouth gently opem it and look inside , then if your koi's mouth is obstucted its a simple matter of hooking it out.
Heres an article I did on the various stages of anesthetics and how to use them :-

https://www.gardenpondforum.com/articles/the-various-stages-of-anaesthetics.5/

Hope this help in the future ?

Dave

HI Dave, I don't know how long the fish had the tumor--she was fine when wintered over and It was very difficult to see who was eating what as you can't see beyond a few inches from the top and I was feeding medi koi that sinks. As soon as I noticed that she could not swallow--I posted and then contacted a vet. She didn't stave to death--she had a tumor closing her esophagus and protruding slight from her gill. The vet said it was most likely cancer. It was very hard to let her go. I do not know how to anesthetize a fish, I have used clove oil to put a fish down that was very ill. Would it be done in a similar way?