How to prevent and treat white head and white mouth disease in farmed grass carp
In home fish summer fry nursery ponds, the skin pigment from the tip of the snout to the eyeball of diseased fish fades to a milky white color, the lips appear swollen, and opening and closing become impaired, thereby causing difficulty in breathing.
White head and white mouth disease is one of the serious diseases harming summer fry fish species (grass carp, black carp, silver carp, common carp, etc.), and it is most harmful to grass carp. It strikes fast and fiercely, and within a single day it can kill thousands upon thousands of summer fry. In severely affected ponds, wild trash fish and even tadpoles can also be infected and die.
(1) Prevention.
① During the first-level stocking stage of fry, a reasonable stocking density of about 225 fish per sq m should be used, which can prevent the occurrence of this disease.
② Keep the water quality clean, with sufficient and suitably sized food, and do not apply manure that has not been fully fermented.
③ Before stocking fry, soak them in a 2% salt solution for 10-15 minutes.
(2) Treatment.
① Rhubarb. Splash it over the whole pond at a final water concentration of 2.5-3.7 mg/L. Before use, for every 1 kg of rhubarb, use 20 kg of 0.3% ammonia water (ammonia content 25%-28%), soak at room temperature for 12-24 hours, dilute the medicinal liquid and residue with pond water, and splash evenly over the whole pond.
② Rhubarb and copper sulfate mixture. Rhubarb 1.0-1.5 mg/L, prepared as above; copper sulfate 0.5 mg/L, made into solutions separately, and splashed over the whole pond.
③ Chinese tallow leaves. Splash over the whole pond at a final water concentration of 2.5-3.7 mg/L. Before use, for every 1 kg of dried Chinese tallow leaf powder, use 20 kg of a 2% quicklime solution, soak at room temperature for about 12 hours, then boil for 10 minutes, dilute with pond water, and splash over the whole pond.
④ Erythromycin. Splash over the whole pond at a final water concentration of 0.05-0.07 mg/L.