Sick Koi - Won't eat

[Andy41]

Hi Everybody,

It's been a while, so i hope everybody is ok.

I need your help with one of my Koi. He's 6 years old, and about 50cm long. Normally he eats like a vacuum cleaner, hovering up all the food, but over the last 5-6 weeks his appetite has declined, and he's showing almost zero interest in food.

The handler where i bought him has been helping, and so far we've treated with a broadband antibiotic, and two types of parasite medicine for different types of worms, but so far nothing has helped.

Symptoms so far are :

1. No interest in food.
2. Some rolling and jumping which is normally associated with parasites.
3. Microscope showed a few worms, but nothing major.
4. Gills are normal colour.
5. Breathing seems slightly elevated but i might be imaging that.
6. Today he started spitting out food and shaking his head as if it hurt to eat.
7. No obvious lumps or bumps on his body.
8. No colour loss.

I'd hate to lose him, so i hope somebody can help here...

Cheers,

Andy.

 

[Andy41]

p.s. He's the one in my profile pic...

 

[Lisak1]

This is a long snot but have you checked his mouth? I’ve heard of koi getting gravel stuck in their mouths which would making eating painful or impossible.

 

[Mmathis]

Can you provide more information about your pond set-up?

1. How big is your pond?
2. other fish and sizes?
3. water parameter tests?
4. climate — what season are you going through at the moment?

 

[Andy41]

Hi Lisa, TurtleMommy,

We checked his mouth.... it looks clear.

Pond is 21,000 litres, 9 other Koi, all smaller than this one, and about 30 goldfish.
Water parameters are measured with test stripes and all parameters appear normal.

We've starting autumn here, and the water temp is around 20C.

Thanks,

Andy.

 

[Lisak1]

I just re-read my post - "long snot". haha. That's what I get for posting on my phone! That should be LONG SHOT.

I'm not a big fan of treating fish (or humans, for that matter) with "just in case" medications. At this point, I think I'd just watch and see what happens.

Have you changed food recently? If he's going after food and appears to want to eat, maybe he just doesn't like the food? Again - another "long snot". haha!

 

[Mmathis]

Could it be that your fish are going into “hibernation” mode?

Totally agree with @Lisak1 about blindly treating! If you have pulled the koi and done a scrape, and have seen obvious signs of illness, that’s a different matter.

 

[Andy41]

Hi Everybody,

Quick update. The place i bought the Koi from did a home visit. We took the fish out, sedated him, and did a gill scrape. This showed that he had Gill flukes. We also scraped the skin again ,and the worms we'd seen there last time have gone. We also checked his mouth for obstructions and didn't find any.

What we think has happened is that after the first treatment some eggs survived - this would explain why he started eating again, and then stopped. When the eggs hatched we then got the second set of symptoms - spitting out food.

So, we've treated again, and the good news is that he's eating almost normally again, and acting much more like normal.

He's visibly lost weight, so he's going to be given a special food to try and boost his immune system and fatten him up and maybe a third treatment at the end of this week to catch any remaining eggs/worms.

All the other Koi appear to be normal.

Thanks for all the suggestions and ideas

Cheers.

 

[Andy41]

Hi everybody,

Last update here.... so it turns out that although the Gill flukes were there and needed treating, that a contributing factor was the dissolved oxygen level.

I can't measure it, but on the Koi handlers advice i put the airstone that normally runs in the winter into the pond and left it running 24/7, and within 2 days all of the fish had perked up, were much more active, and much more interested in food.

Low oxygen would also have supressed the Koi's immune system a bit, leading to more extreme reactions to gill flukes and other nasties.

So, the lesson to be learnt here.... check *everything*.

Again, thanks to everybody for all the suggestion.

Cheers,

Andy.

 

[Lisak1]

Glad to hear things have leveled out @Andy41 .

And a good reminder - it's not necessarily ONE thing that can be affecting your fish. It could be ONE thing that leads to another that exacerbates yet another.

 

[poconojoe]

Awesome to hear a good ending to your story!

I keep two air stones going at all times. I have a tiny splitter and two tiny valves so I can regulate the air flow individually to each stone.

For the winter (it gets cold here, zone 6a) I raise the air stones up to about 12 inches below the water surface. I don't want to send cold air down to the bottom where the fish are hibernating. I tie a string to the air stones and secure the string to a rock on the ground.