How to Treat Koi Gill Flukes (Best Fluke Treatments)

Fluke is a common parasite that is found in almost every kind of water. It affects the pond fishes and the problem the fishes face is called skin fluke and gill fluke. These minuscule species attach themselves to the body of the fish, and this is the way they feed themselves from the skin and gill tissue of the fish. This creature is microscopic so you can only find the issue if you scrap a piece of skin from the gill area and check that under the microscope.

You cannot identify a gill fluke in naked eye, as these are barely 3mm in length, slightly longer than the skin fluke. It has a cylindrical body shape and the head has a dark spot. A set of hooks called opisthaptor helps it to attach to the feeder or the koi fish.

Koi Gill Flukes

Cause of Koi Gill Flukes 

The gill fluke problem is mostly caused by the newly brought fishes in the ponds. Sometimes even the birds carry this microorganism when they come to drink water from the water body.

You can find the worm part of the fluke stuck in the skin of the fish and then you need to apply certain kind of drugs to eliminate the ailment. This is a kind of parasite and it stays on the body of the fish until you notice it and omit it by antifungal or antibacterial medicine.


The flukes are not fed on any particular fish for a long time and eventually leave its feeder. At the early stage of life a koi fish may get infected with this parasite.

They cause irritation and inflammation to the part they are stuck, like the gill.  The koi starts eating less and feeling lethargic due to the stress, which may later cause serious illness. The problem can grow if the number of flukes gets increasing. Its health will worsen and it will spread this parasite to other fishes of the same pond. So if you realize any strange acting in a single koi of your pond, start looking for reason behind it before it starts spreading.

Safe treatments

Remedies like salt is most common and natural one which is also without any side effect. But you need to bath the particular affected fish in salt water to get the result. According to Mypetcarejoy the safe treatment options could be following. So we are here discussing some of the options.

  • Aqua prazi – the Aqua Prazi treatment is one of the best fluke treatments for the koi. This is totally safe for the koi and goldfishes. Also the eco system does not lose its balance due to the application of this chemical. Praziquantel is present in this medicine and you can use 10gm per 100 gallon water. It takes 24 hours to start enacting. You can reapply it after 3 to 7 days. In a 2 weeks course it will completely demolish the fluke problem from a koi pond.
  • Ecolab disease treatment – this is an alternative of Ecolab broad spectrum disease treatment. Malachite green and formalin are present in this medicine. This is not a practiced medicine for the fluke treatment of koi but this is an effective one. Along with flukes it also serves to cure costia and other certain types of fungal infection.

Read More:


As eggs of any worm do not get affected by any treatment, you can double treat the water with anti worm means. Also feeding the fish with all the necessary nutrients in the months of summer helps to boost its immunity and thus fighting any worm related disease.

Also maintain the healthy number of fishes as too many fishes may not stay healthy in little amount of water and thus will contaminate the water quality, causing various diseases. Treat the water with activated carbon to keep the water healthy and fresh.


Leave a Comment

Your email address will not be published. Required fields are marked *