The causes, types, and severity of fish diseases vary, whether they are common among natural breeders or established for this purpose. These diseases may be caused by bacterial, viral, or even fungal infections of fresh, healthy fish If the species are contaminated, it may be caused by water or food. Sometimes the natural enemies of waterfowl and even fish in the environment can cause certain diseases that affect fish.
In terms of causes, there are also many similarities between diseases affecting fish and many diseases affecting animals, the reasons are limited to: bacteria, fungi, parasites and viruses.
In recent years, with the emergence and spread of intensive farming, many diseases have spread, especially due to the process of intensive and mass reproduction in a small area has accelerated the spread of the disease, resulting in a large number of deaths The return has had a significant impact.
Experts believe that the increase in the number of farming units per unit area helps to concentrate waste in the environment, thereby violating one of the factors of the natural balance of the environment