* Injury: Scales can be easily damaged by physical trauma, such as being bumped or scraped against objects in the pond.
* Disease: Several diseases can cause koi fish to lose their scales, including bacterial infections, fungal infections, and parasites.
* Nutritional deficiencies: A lack of certain nutrients, such as vitamin C, can lead to scale loss.
* Water quality issues: Poor water quality, such as high levels of ammonia or nitrite, can also cause koi fish to lose their scales.
* Genetics: Some koi fish are more likely to lose their scales than others due to genetic factors.
If you notice that your koi fish is losing scales, it is important to determine the cause so that you can take steps to treat the problem. In some cases, scale loss can be a sign of a serious underlying health condition, so it is always best to err on the side of caution and consult with a veterinarian if you are concerned about your koi fish's health.