Disease prevention techniques for farmed fish to achieve an effective production cycle

Fish farming is becoming one of the important economic development directions in many rural and coastal areas. However, disease is always one of the major challenges, directly affecting productivity and economic efficiency. To help farmers proactively prevent and reduce risks, Vemedim would like to share the following fish disease prevention techniques, applicable to both cage-cultured fish and pond/lake-cultured fish, right below.

Measures and techniques for preventing disease in farmed fish

To ensure a successful fish farming season with high productivity and minimized disease-related risks, applying integrated disease prevention measures is essential. These fish disease prevention techniques mainly aim to help fish grow healthily, increase growth rate, and improve economic efficiency for farmers. Below are guidelines to help farmers proactively prevent disease from the beginning of the farming season:

1. Cage fish farming

Cage and raft fish farming on rivers, lakes, or bays requires special attention to the surrounding environment and care procedures, because cages limit the ability to control water quality. Some important measures include:

Clean the cages and surrounding area: Remove debris, waste, and algae attached to the cages; ensure the surrounding water flow is not polluted.
Choose quality fingerlings: Only stock healthy fish that are not deformed or injured; this is the first fish disease prevention technique farmers need to apply to reduce the risk of disease transmission.
Manage feeding properly: Use quality feed in the correct amount, avoiding excess feed that pollutes the water.
Boost fish immunity: Add vitamin C to the diet, or use disease-prevention products according to the manufacturer’s instructions to improve fish resistance.
Plan stocking time carefully: Choose a time when fish can adapt easily and the water environment is stable to reduce stress.
Adjust stocking density: Do not stock too densely, as this causes fish to compete for feed and become stressed more easily.
Use fishing gear and harvest properly: Use nets, floats, and boats appropriately to minimize collisions and injuries to fish.

*The first fish disease prevention technique is to choose healthy, high-quality fingerlings*

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2. Pond/lake fish farming

For ponds and lakes, the environment is better controlled, but the following synchronized fish disease prevention measures and techniques still need to be implemented:

Clean the water environment and pond

Only use clean water sources, avoiding polluted water or water containing pathogens.
The pond should be open and clear, with no dense vegetation around it to prevent parasites from hiding.
Before stocking fish: drain the water completely, dry the pond bottom, and apply 10–15 kg of lime per 100 m² to disinfect and improve the bottom.
Remove leftover feed and fallen leaves to avoid excess feed causing pollution.

*One fish disease prevention technique for pond culture is to strictly manage water quality*

Boost fish immunity

Select healthy fingerlings that are not injured or deformed.
Do not stock fish that are too small and avoid overly dense stocking.
Avoid thermal shock: When releasing newly purchased fish, gradually equalize the temperature by slowly adding pond water into the container/basin holding the fish, or soak the fish bag for 15 minutes before releasing the fish into the pond.
Before stocking, bathe the fish in 2–3% salt water for 10–15 minutes to remove parasites attached to the body.
Do not use fresh manure; manure must be composted with lime (4–5 kg per 100 kg of manure) for 20 days.
Apply lime periodically to the pond (1–2 kg per 100 m³ of water, twice a month) to stabilize pH and eliminate pathogens.
Check pH using litmus paper or a specialized test kit.
Use disease-prevention medicines as recommended before the outbreak season.

*Applying lime periodically to the pond is a fish disease prevention technique to stabilize pH and eliminate pathogens*

The relationship between disease-causing factors

Fish health depends on the interaction between the environment, disease-causing agents, and the fish’s resistance; fish disease prevention techniques also affect these factors:

Environment: Includes physical and chemical factors (temperature, clarity, oxygen concentration, CO2, NH3). A polluted environment creates favorable conditions for pathogens to develop.
Disease-causing agents: Bacteria, viruses, fungi, and parasites can exist in water, feed, or fingerlings.
Fish resistance: Weak, stressed, or undernourished fish are more susceptible to disease.
Fish become diseased when all three factors combine. Therefore, effective prevention should focus on:
Improving the environment: Clean cages and ponds, treat water, and control organic matter with Vemedim Vime-Protex, Vemedim Vime-Iodine.
Limiting pathogens: Use disease-free fingerlings and inspect them before stocking.
Boosting fish immunity: Provide adequate feed quality and quantity, supplement vitamins and minerals with Vemedim ANTI – SHOCK, Vemedim GLUSOME 115, Vemedim ADE B.complex, and maintain a suitable stocking density.

*To keep fish healthy and growing evenly, paying attention to feeding is definitely an important fish disease prevention technique*

Integrated disease prevention is a key factor in ensuring fish grow healthily, minimizing losses due to disease, and improving economic efficiency for farmers. By fully implementing the above fish disease prevention measures and techniques, farmers can better control disease risks. Vemedim hopes the detailed guidance in this article will be a useful reference, helping farmers proactively protect their fish stocks, achieve high productivity, and ensure safety in every farming season.