Koi disease: What causes it and what are the cures?

An unfortunate reality in the life of a koi owner is the existence of koi disease which inevitably must be dealt with at one point or another. Different types of koi disease are very common and they must be dealt with swiftly and completely to prevent the death of the fish and ensure complete recovery.

Unlike the medications used to treat humans, the way koi and other types of fish are treated is by adding the medication to the water itself. Let's look at a few types of koi disease, how they can affect the fish, and how they can be dealt with and eliminated swiftly.

Koi viruses - believe it or not, one of the most common viruses to infect koi is called koi pox. This koi disease, which appears as clear waxy looking spots on the fish, is not really harmful to the fish and will usually disappear on its own especially when the water begins to warm during the summer months. A common type of koi vaccination added to the pond water can help prevent the koi disease koi pox.

Koi bacteria - there are several types of bacteria that can infect the koi and these types of koi disease can be a bit more serious. They include gill and fin rot, various ulcers ailments of the mouth. When your fish infected with one of these types of bacteria is usually pretty easy to see. Fin rot is especially easy to recognize because it looks as if the fins and tail of a fish have been chewed on. It is important to treat the pond water with an antibacterial liquid if any of these types of koi disease are discovered. Another type of bacteria, dropsy, requires that the koi be injected with a treatment or have the medication added to their food.

Koi fungus - Saprolegnia can cause cotton wool looking growths that appear on flesh wounds of the fish's body. While not contagious, they can cause complications on the koi they are located on and in the worst cases the koi should be dipped in a bath of pond salt.

Koi parasites - these can include Trichodina, Whitespot, Ichthyobodo and Chilodinella and will attach themselves directly to the skin of the fish and feed on mucous membranes and are a serious health concern for Koi fish. While these are merely single celled organisms, there are many types of larger parasites which have many cells and they can include gill and skin flukes, fish lice, anchor worm, tapeworm and leeches. Treatment for these parasites can include salt baths and an agent known as malachite green.

You must pay careful attention to your fish and notice any developments that seem out of the ordinary. Some of these types of koi disease are harmless and may not readily make themselves known, while others can cause sickness or even death to the infected fish. Learn the signs, what to look for, and the treatment and you can help your Koi fish live a long and healthy life through avoiding or overcoming koi disease.