Prevention and Treatment Methods for Carp Pox Disease in Crucian Carp Farming

In recent years, the farming structure in my region has generally been dominated by crucian carp as the main species, and the incidence rate of crucian carp diseases has also appeared increasingly high. Carp pox disease in crucian carp, which almost never occurred in the past, now also occurs from time to time. This disease generally occurs after late autumn and rarely causes fish death, but it seriously affects the commercial value of crucian carp.

The symptoms of carp pox disease in crucian carp are: in the early stage, small milky white spots appear on the body surface of the diseased fish, covered with a very thin layer of white mucus. As the disease progresses, the size and number of the white spots gradually increase and expand, spreading over the whole body. Because the epidermis of the affected part is stimulated by something, it thickens and forms a proliferation, which can rise 1 to 2 mm above the fish body surface and generally cannot be rubbed off. It is currently considered a viral disease.

Prevention methods for carp pox disease in crucian carp: (1) Strictly and thoroughly clear the pond with quicklime; (2) Strictly control the quality of fry and fingerlings, and refuse to purchase fish fry from disease-affected areas; (3) Maintain sufficient dissolved oxygen in the rearing pond; (4) Regularly splash disinfectant drugs over the whole pond; (5) Adjust the farming structure by temporarily not farming crucian carp and common carp.

Treatment methods for carp pox disease in crucian carp: On the first day, use quaternary ammonium salt (commercial drugs such as: Dijundu, high-efficiency quaternary ammonium salt) at the dosage stated in its instructions, and splash it over the whole pond; on the second day, use quaternary ammonium salt complexed iodine (commercial drugs such as: iodophor, etc.) at 50% more than the stated dosage, and splash it over the whole pond. This can cause the proliferation on most diseased fish to fall off, thereby restoring the commercial value of the diseased fish.

In short, there is currently far from any drug that can completely cure this disease. The author believes that prevention should be the main approach. Ponds that had the disease last year should preferably change their farming structure, with grass carp, black carp, bream, etc. as the main farmed species. These fish generally do not become infected with this disease. For ponds that had the disease last year, fish bodies should be checked frequently after September. If the disease begins to occur, treatment or pond clearing should be carried out early to reduce economic losses.