Prevention and Treatment Methods for Several Common Diseases in Perch Farming
Perch have relatively strong disease resistance and are not prone to illness under natural conditions. However, in artificial high-density farming, because their living environment and space change greatly, disease can easily occur with the slightest carelessness. Disease prevention must be strengthened, and drug disinfection of farming ponds and feeding platforms should be carried out regularly; when disease is found, treat it early. Common fish diseases include:
1. Enteritis
The abdomen of diseased fish is distended, the anus is red and swollen, and squeezing the abdomen causes pale yellow mucus to flow out. It is mainly caused by feeding stale or spoiled feed. For treatment, oxytetracycline can be mixed into bait and fed, using 10 grams of medication per 50 kg of fish, halved from the second day onward, and fed continuously with bait for 6 days. Norfloxacin at 2 grams mixed into bait can also be used.
2. Gill rot disease
Diseased fish have dark body color, swim alone at the water surface, and respond sluggishly to external stimuli. When the gill cover is opened, the gill filaments are pale and the gill lamellae are rotting. The cause is that after heavy rain the water quality becomes turbid, making infection with this disease easy. This is especially true for cage farming after heavy rain, when upstream sediment flow strikes the fish body, making perch highly susceptible to this disease and causing great losses. For treatment, erythromycin can be fed, using 0.5 grams of medication per 50 kg of fish, continuously mixed into bait and fed for 6 days. At the same time, use 0.4 ppm strong chlorine to splash the entire pond or cage for 3 consecutive days; the treatment effect is relatively obvious.
3. Hemorrhagic disease
The bases of the pectoral fins and dorsal fin of diseased fish are red and swollen and congested; diseased fish move slowly and their feeding decreases. This disease is caused by a virus and is highly contagious. For treatment, a mixture of moroxydine and antibiotics can be fed, using 0.5 grams of moroxydine and 1 gram of norfloxacin per 50 kg of fish, mixed into bait and fed for 6 consecutive days. At the same time, splash the pond with 0.4 ppm strong chlorine over the whole pond once a day for 3 consecutive days.