Koi Care Basics Blog

It is important to know what symptoms to look for when protozoa or parasites invade your fish and how to treat them. If left untreated they adversly affect Koi health.

We will start by covering some of the more common types of protozoan disorders.

In Chilodonella the entire body of the fish is covered with a heavy slime coat. Treatment for Chilodonella requires the use of Metronidazole or quinine sulfate..

When Koi health is affected by Eimeria your fish appear emaciated and have sunken eyes. To treat them you must make a medicated food with either tetracycline or oxytetracycline and feed this to them once a day for 10 days.

Another comon protozoal disorder is Ichtyobodo (Costia). Koi that are affected with this disorder have small areas on their bodies that have a blue-gray tinge that looks like excess mucous. Treat these fish with a fungicide/protozoacide dip/bath treatment in the water or quinine sulfate.

When ICH (Ichphyophthirius) strikes your Koi will appear to be covered in white sand or grit and some fish breathe heavily. These fish need to be treated with quinine sulfate or copper sulfate

When Koi health is affected by Heteropolaria (Episapylis), the fish can be seen flashing (Flashing is a fish behavior characterized by rapid, glancing contact with a solid object in an effort to displace an external parasite or other irritation, so called because the light colored underbelly of the fish is thus exposed to momentary view.) and rubbing on objects in the pond, even in the spring when they don’t have any visible signs of the disease. Then in the summer they develop ulcers and bacterial infections.

Usually, if you have treated your pond for parasites and your Koi are still flashing, then Heteropolaria is the cause. Treat this Koi health issue with quinine sulfate and then treat the secondary bacterial infections.

Hexamita, also known as Hole-In-The-Head Disease, is indicated when your Koi exhibit erosions on their heads and gill plates. In severe cases the disease follows the lateral line. The preferred treatment for this disease is the use of quinine sulfate.

Finally, in Trichodina, symptoms include heavy breathing, the fish have a heavy slime coat and appear to have round, flat parasites on them. This protozoal disease should be treated with a fungicide/protozoacide dip/bath treatment in the water.

Next we’ll discuss how parasitic disorders affect Koi health.

When the problem is Gill Flukes, also known as Dactylogyrus, the Koi will gasp for air at the top of the pond. They also sometimes flash, rub against objects in the pond and their gills may develop bleeding. To cure this disorder you need to treat your pond water with an anti-parasitic powder. Treat secondary problems, if there are any after the flukes are gone, with an antibiotic product.

A goldfish with anchor worm

In the case of Anchor Worms, or Lernaea, your Koi will exhibit small pimples on the skin or reddened areas with a white threadlike worm sticking out. To treat Anchor Worms you need to treat your pond water with an anti-parasitic powder.

When Koi health is affected by Fish Lice (Argulus) the fish will have small, round clear to white objects stuck all over them. Your Koi will flash and scratch against objects. Again you should be treating your pond water with an anti-parasitic powder.

If your Koi are infested with Leeches you will see flat and thin brown objects stuck all over the body of your fish. As before treat your pond water with an anti-parasitic powder.

A Tapeworm infestation will cause your Koi to have swollen bellies even if they have not been fed in a couple days. While there is no suitable treatment for severe bloating you can treat for Tapeworm with an antiparasite powder.

In summary you need to be vigilant about keeping a close eye on your Koi and also be aware of what types of treatments are appropriate for different conditions. This article is not meant to replace the advice of a liscenced veterinarian. It is intended for informational purposes only. If you are ever unsure about the cause and/or proper treatment of your fish, make sure to contact your veterinarian so that you can ensure optimal Koi health.

To learn more about Koi health, Koi keeping and Koi ponds visit my website.

Alan Deacon
KoiCareBasics.com

Mainly used for decorative purposes in water gardens and outdoor ponds, Koi, or Japanese carp are ornamental domestic varieties of the common carp. Although they are quite beautiful and hardy these fish are prone to Koi bacterial infection.

This occurs most often when they come in contact with Aeromonas or Pseudomonas bacteria. These naturally occurring bacteria are found mainly in the water of ponds and lakes. They do not exist in tap water because of the chlorine it contains.

However, if you fill your pond or water garden with tap water you will discover that the bacteria can eventually be found in this water too. Once the chlorine evaporates Aeromonas and Pseudomonas are quick to move in. Unfortunately they then have the ability to cause Koi bacterial infection.

The good thing about these bacteria is that they don’t cause much harm when found in low quantities in a clean and healthy pond.

Also, the outer coating or epidermis of the fish protects them from infection. However, harmful bacteria can infect your Koi when its epidermal layer is broken because then the bacteria can penetrate it’s outer cover.

Not only does it harm the fish already present in water, but can spread very rapidly too.

Commonly, when the Koi’s dermis layer is exposed to bacteria, infection can start to spread rather rapidly. This process takes place when flukes use their haptens, resembling small fishhooks, to attach themselves, thus attracting harmful bacteria onto the surface of the fish.

Another thing that can break the Koi’s slime coat is a puncture or scratch from a sharp object, such as a rock, that exposes it to bacteria.

The Koi can also be exposed to bacteria due to poor water quality or stress caused through overcrowding or moving the fish from one pond to another.

So how can these infections be treated? If you are interested in trying some home remedies you can follow the procedures below.

Koi bacterial infection can be present in wounds either smaller or larger in size. Therefore separate procedures are followed to treat them.

When treating small sores use a paper towel to dry off the wound. Next, soak the sore in a solution of hydrogen peroxide on a cotton swab for 30 seconds before you place the Koi back in the water. You need to repeat this procedure for 3 consecutive days.

The treatment for larger sores is similar. The only difference being, after following the same procedure and drying off the wound again, you need to apply a Debride Medicated Treatment on the sores. This procedure also needs to be followed for 3 consecutive days.

However, if this treatment doesn’t work effectively, you may need to seek the advice of your veterinarian. You can also feed medicated food to help heal your fish faster. This method may not always work, especially in fish very small in size.

This advice is for informational purposes and is not intended to replace proper medical treatment by a licensed veterinarian when treating stubborn or severe cases of Koi bacterial infection.

Alan Deacon
KoiCareBasics.com