Koi diseases
Koi diseases occur regularly, especially if the water composition or water quality is not correct. If koi have been infected, it is important to observe the symptoms well and to determine what disorder fish are suffering from.
A diseased koi can be recognized by its listless behaviour or by the pots on its skin. Other symptoms are rubbing its skin against the pond bottom or an other deviating behaviour. The most common diseases include:
| Fin rot | Skin worm | Trichodina |
| Swollen belly dropsy | Koi herpes | Chilodonella |
| White spot | Hexamita | Fish tuberculosis |
| Carp louse | Saprolegnia | Oodinium |
| Gill worm | Costia | Cryptobia |
| Tape worm | Protozoa | Carp smallpox |
Preventing koi diseases
If a koi is diseased, different kinds of medicine are to be had. It is always wise to put diseased fish in quarantine outside the pond. A better thing to do is to prevent koi diseases:
- Strong fluctuations in water quality may be the cause that the resistance of a koi will decrease, thus causing koi diseases to start developing. Regularly Inspect and measure the pond water quality. This can be effected easily using a water test kit.
- To keep the water quality to the level a proper filter brings relief. Filthy particles in the water will be absorbed by it. If a pond filter should also contain activated carbon, the pathogenic organisms can be filtered from the water.
- To prevent fish from falling ill in spring it is important to feed them during the summer months on a qualitatively perfect feed, all important nutrients, vitamins and minerals being present to a considerable extent. In this way resistance of koi during the winter months will be kept to the level.
- Do not introduce too may koi in your pond. The standard is maximum 1 koi per 1,000 litres of water.