One day, koi fish's stomach suddenly became bigger and bigger, and the scales were propped up, but he would take the initiative to grab food.

This should be a symptom of vertical scale disease.

The body surface of the diseased fish swells, some scales expand outward like pinecones, the scales are swollen at the base, and translucent or bloody exudates accumulate inside, which makes the scales stand up. When you press lightly on the scales, a lot of watery liquid will gush out from the base of the scales, and the scales will fall off. Sometimes accompanied by fin base, slight skin bleeding, abdominal swelling and other symptoms. Most diseases of tropical fish are caused by frequent water change. If the fish is unfortunately scaling, it is necessary to replace the water in the tank, adjust the water quality in the tank, and replace the old filter material to reduce the secondary damage of harmful substances in the water to the fish. Pay special attention to the decrease of fish activity and food intake, because the scales will only tilt slightly in the early stage. If we can find them early, it will be the most effective treatment period. You can use 50 liters of water to bathe 1 g sulfamethoxazine preparation or oral disinfectant and antibiotics, and then raise the temperature to 32 ~ 33℃. Please pay attention to the cleanliness of the medicine color and water quality in the tank and provide adequate aeration. If the water quality becomes turbid within 24 hours, it is necessary to change the water immediately and filter it with activated carbon, and then add medicine for treatment after the water quality is clear and stable. After 3 days of medicated bath, it will obviously improve. At this time, you can put activated carbon in the filter tank to filter out the medicine, and then it will have a good curative effect. (Remember to take out and discard the activated carbon after filtration). After one week, you can start to change the water to 1/3 and feed a small amount. After the fish's food intake and scales are obviously smooth and normal, it means that they are healthy again. Although the scale edge will be slightly brown, it will not be affected, and its original luster will be restored in about 20 ~ 30 days.

Edit this paragraph for prevention and control.

1. Mix 1% salt solution with 1% baking soda, soak the fish for 10 minute, and it will take effect after repeated medication. It is also effective to use low-dose splashing in an aquarium with water solubility of 100 kg. 2. Furacillin powder 0. 1g was added with 2 gentamicins and dissolved in an aquarium of 80cm×50cm×40cm. Long-term medicinal bath has certain curative effect, especially for sick fish in the early stage of illness. 3. Baking soda and salt bubbles are ok, but the effect is slow. 4. Pulverize trimethoprim disulfonate tablets and put them into water. 5. Penicillin/chloramphenicol/gentamicin immersion bath also has a certain effect.