RED SPOT DISEASE IN KOI FISH
Koi fish, also known in Vietnamese as Japanese carp, and in Japanese as Nishikigoi. Originally, Koi fish originated from China, but 200 years ago, the Japanese bred them into a completely different species (Koi Kohaku, Koi Tancho, Koi Sanke, Koi Shiroi…), and they became a symbol in Japanese culture.

Koi fish are very susceptible to disease if the pond water environment is not well maintained and water quality parameters are unstable. The first step when treating a disease is to measure the water quality parameters (pH, NO2, NH3,..) of your Koi pond. Only by checking the pond's water quality parameters can you accurately determine if the disease is caused by bacteria or changes in the water environment.

Disease Symptoms
This disease causes red hemorrhagic spots to appear all over the fish's body, scales fall off in patches, the fish eats poorly, and swims sluggishly. When the disease worsens, fin bases and fin rays become ragged and gradually erode. Hemorrhagic skin areas become inflamed and ulcerated, with pus, surrounded by parasitic fungi, the fish's gills become pale, and the skin color turns dark. If red spot disease in Koi fish persists for 1 to 2 weeks, the fish may die.
Causative Agents
Often, when catching or transporting fish, they can easily get abrasions, or during farming, fish can experience stress, high temperatures, or poor water quality, leading to infection. Red spot disease in Koi fish is caused by rod-shaped bacteria with the scientific name Aeromonas Hydrophylla or it can also be caused by Pseudomonas.

Effective Treatment Methods

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Disease Caused by Water Environment
- When Koi fish are found to be diseased, they need to be separated into a dedicated treatment pond for active treatment.
- Regularly change the water in the pond, dissolve powdered lime in water, and evenly spread it throughout the pond at a dosage of 2kg/100m2/2 weeks.
Bacterial Disease
- Discontinue feeding, clean around the pond, and perform thorough water changes.
- Treat with Tetra max 10g/1m3 + salt 1kg/1m3, dilute and spread evenly throughout the pond for 3 consecutive days. Change water after each treatment.
- Mix 3g/1kg of feed, can be coated with Atomic plus binder for 10 – 15 minutes before feeding.

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Than Vuong Technical Department




