Prevention and Treatment of Hemorrhagic Edema Disease in Yellow Catfish Aquaculture

Hemorrhagic edema disease in yellow catfish is caused by bacterial infection. This disease is most harmful during fry or adult fish aquaculture, and is especially prevalent during fry rearing, with a mortality rate as high as 80%. In high-temperature seasons, the disease breaks out suddenly, strikes fiercely, and spreads quickly.

Symptoms: The body surface of diseased fish turns yellowish, with increased mucus; the skin of the pharynx ruptures and becomes congested, forming round holes; the abdomen becomes distended, the anus is red and swollen and protrudes outward; the head is congested, the dorsal fin is swollen, the bases of the pectoral and pelvic fins are congested, the fin rays ulcerate, and in severe cases the abdomen splits longitudinally from the pectoral fins to the pelvic fins, with bile seeping out. A large amount of bloody fluid or yellow gelatinous material accumulates in the abdominal cavity, the stomach and intestines contain no food, the stomach is pale, the intestines are filled with yellow fluid, the liver is earth-yellow, the spleen is necrotic, and there are mold-black spots on the kidneys.

Prevention and treatment: Maintain good water quality, keeping the dissolved oxygen content of the pond water above 5 mg/L; appropriately reduce the stocking density of fry. After the disease occurs, disinfect the water body once a day for 3 consecutive days. At the same time, add 0.6-0.7 g of tetracycline per kg of feed to make medicated bait and feed it, once a day for 3 consecutive days; when feeding fish meat paste, 1% table salt must be added to the feed.

In addition, when examining the symptoms of the fish, please be as detailed as possible, from head to tail symptoms, whether there is any abnormality in activity, feeding conditions, dissect a few diseased fish to look at the conditions of the internal organs, etc. This will help with diagnosis.