Anchor Worm?

[fly4koi]

Today I saw a koi with a white string that's hanging off the side towards the tail, I think it's about 1.5" long, if this is anchor worm, do I need to treat the whole pond or just the fish alone?
I found this product: Microbe-Lift Lice and Anchor Worm Treatment, or ProForm LA Lice & Anchor Worm Treatment
Thanks in advance. This past winter has been tough and I am quite upset that I just lost yet another koi...

[icu2]

Sure does look like anchor worm to me too.
One treatment seems to be application of a strong potassium permanganate solution on a cotton swab one at a time to
make the parasite release it's "hook" on the fish and remove it with tweezers. You want it to release its hold to prevent breaking
part of the body off and leaving the head in the fish creating the chance for it to get more infected. I'd dab iodine on the wound
after removal.
I've not used either of the meds you found but have seen the Proform LA suggested in other articles. It looks like the effective
ingredient in either med is Diflubenzuron.
I think I'd remove them singularly with tweezers if there aren't many and then treat the whole pond as they lay eggs and sounds
like they will reproduce without medication to kill them.
Some links:

https://www.koiphen.com/forums/showt...263#post964263

https://koiorganisationinternational...es-anchor-worm

https://www.koiphen.com/forums/showt...ive-Discussion
(At the end of Part 13)

Diflubenzuron is commonly used as an insecticide for greenhouse use. This powder works well in eradicating anchor worm(Lernea)and fish lice(Argulus). One gram will treat 3000 gallons. It is quite forgiving and an overdose usually will not cause irrepairable harm. The parasites should be removed by soaking them in iodine and pulling them carefully with a tweezers. Sedating(described below)the fish will prevent uncontrolled thrashing and further damage to the fish during this process. No ill effect is noted from sedation.

There are liquid forms (Dimilin) on the market. Follow the label directions.

I thought they stopped making Dimilin but I found some on Amazon. My old bottle instructs to dose and then redose to kill
hatchlings 3-5 days after the first.
https://www.amazon.com/Dimilin-X-Gol.../dp/B01IWEPKAU

[fly4koi]

Thank you, ordered the Dimilin.
I think my water is generally cold enough (60F) so that most of the larvae don't make it into adult stage which explains why I haven't seen an huge infestation.

Do you think the mirror kois are more prune to diseases because of the lack of scales?

[icu2]

No idea if scaleless koi are more prone to anchor worms than scaled. Maybe someone else knows?

Western WA is suppose to warm up quick in the next few days. My bottle shows it only takes a teaspoon per 500 gallons and
my 8 oz. bottle would treat 25,000 gallons. I think you'll have plenty if you got that one on Amazon (1/2 gallon).

[fly4koi]

Yes, it'll be very warm this weekend, but my pond is in the shade so maybe it'll get to low 60F only.

[kdh]

Thank you, ordered the Dimilin.
I think my water is generally cold enough (60F) so that most of the larvae don't make it into adult stage which explains why I haven't seen an huge infestation.

Do you think the mirror kois are more prune to diseases because of the lack of scales?

just the opposite