Home

System

Info

Koi ailments

An adult Anchor worm can grow to about 3mm long. They attach to fish with hooks that penetrate the skin. If the point of penetration is damaged, an infective entry point for bacteria is created.

Cross infection occurs where two or more animals from different sources are put into contact with each other, allowing any infectious agents to be transmitted from one to the other.

Ecto-parasites are parasites that live on the body surface of the fish, such as the skin, fins and gills. This is in contrast to endo-parasites which live inside the fish, in the gut, blood, or organs.

Egg fungus is a fungal growth on eggs that can be rampant and kill incubating eggs. It usually takes several days to take hold.

Flashing is the response seen on fish that are irritated by parasites, flicking and scratching against the pond edges and baskets to free them of their irritation.

Free living stage(s) refers to the stage(s) of a parasite that occur in the water, rather being attached to (or living within) the fish.

Haemorrhaging is reddened areas or red streaks on the skin or internal organs, caused by leakage of blood vessels. It is often a sign of a bacterial or viral infection.

An opportunistic pathogen is a disease causing organism (like bacteria) that will try to colonise a weakened fish given half a chance. Stressed or susceptible fish will be more open to infection.  

A pathogen is an organism or substance that causes disease. In the case of Koi there are plenty of little parasites that like to take a grip, like fish leech and lice and anchor worm. There’s also a huge variety of bacteria, all of which must be accurately diagnosed before treatment.

Pop-eye is a condition in which one or both eyes bulge out from their sockets. In the case of dropsy, both eyes are usually involved. The condition is also referred to as exophthalmia or exophthalmos.r

Trichodina, chilodinella and whitespot are microscopic parasites that live on the exterior of fish. They cause irritation and can often cause fish to secrete excessive quantities of mucus.

Whitespot is a potentially lethal parasitic disease which manifests itself as thousands of tiny dots.

Systemic means affecting the whole body. Systemic infections are sometimes life-threatening and can be difficult to treat. 

Medication / Treatment

An anthelmintic or anthelminthic, is a chemical treatment effective in destroying worm-like parasites such as tapeworm and flukes.

Formalin is an anti-parasitic treatment that sloughs off the layer of mucus that covers a fish, killing or paralysing any parasites.

Malachite green is a fungicide. In conjunction with formalin it is also used as a disinfectant. It prevents infection developing at the sites of parasitic wounds.

Potassium permanganate is a pond disinfectant, usually bought in crystal form. It should be mixed some time before use, but should not be stored in solution form. It is hard on filtration bacteria, so don’t use it too early in the Koi season.

The placing of Koi in a
salt bath is an effective way of dealing with some external parasites or with clogged gills after transportation. Solutions and times vary. Remember that only cooking salt (not table salt) should be used.

Systemic treatment is a method of treatment that works throughout the body. It’s usually applied orally (soaked into the food) or by injection.

Topical treatment is a method of treating a localised lesion by placing medication directly onto the affected area.