Prevention and Control Methods and Key Technical Points for Fulminant Disease in Cultured Puffer Fish

[Symptoms of fulminant disease in puffer fish]The main symptoms of diseased puffer fish are congestion at the base of each fin and in the fin rays; in severe cases, the fin rays, upper and lower jaws, eyes, and the area from the base of the dorsal fin to the caudal fin all show severe congestion. Sometimes there is bleeding in the orbital cavity and exophthalmos. In some cases the gills show varying degrees of decay with abundant mucus. The intestinal wall is congested and there is no food in the intestine; in some cases there is pale yellow mucus in the intestine; the liver is congested or blood-engorged; the gallbladder is enlarged; the spleen is somewhat black. Severely affected fish swim wildly and dash about erratically, or lie motionless on their side at the bottom, and finally die of exhaustion. The mortality rate of this disease is relatively high; mass deaths begin 24 hours after symptoms appear. The risk is extremely great.

[Prevention and control methods for fulminant disease in puffer fish](1) Prevention of fulminant disease in puffer fish: ① Before releasing fry, thoroughly clear and disinfect the pond; under normal conditions, disinfect once every 10-15 days with 0.2-0.5 mg/L bleaching powder; ② Purchase high-quality fry and fingerlings and raise them at appropriately low density; before the fingerlings are put into the pond they must be disinfected with medication, commonly by soaking in 2%-4% salt water for 10-30 minutes; ③ Do not feed rotten or spoiled bait; live and fresh feed must be disinfected before feeding; regularly splash bleaching powder around the feeding platform for disinfection; disinfect the feeding platform daily and expose it to the sun frequently; ④ During disease seasons, regularly use medication for prevention and mix antibiotics into the bait; ⑤ Strengthen water quality management, siphon off waste 1-2 times per week, change water 2-3 times per week, each time changing 20-50 cm of water; ⑥ When diseased fish or dead fish are found, remove them promptly, bury them deeply or burn them, and strictly disinfect tools to avoid cross-infection.(2) Treatment of fulminant disease in puffer fish: ① Splash 10-20 mg/L quicklime over the whole pond; ② Use 0.5-1 mg/L bleaching powder to kill pathogenic bacteria; ③ Splash 0.5 mg/L oxytetracycline hydrochloride over the whole pond, using it 2-3 times consecutively; ④ Splash 0.4-0.5 mg/L furazolidone over the whole pond; ⑤ Mix 0.4-0.5 g norfloxacin per kg of feed and feed it, using it for 5-7 consecutive days; ⑥ Add 0.3-0.5 g oxytetracycline hydrochloride per kg of feed and mix into the bait for feeding; ⑦ Add 0.1-0.2 g allicin and 0.1-0.2 g vitamin C per kg of feed and mix together into the bait for feeding, using it for 3-6 consecutive days.