In aquaculture, the phenomenon of fish with raised scales (scales sticking out like a pinecone, swollen abdomen) is not uncommon. This condition often appears when the farming environment deteriorates, fish are stressed, or they become infected with bacteria, leading to slow growth, a sharp decline in survival rate, and major economic losses. To help fish farmers recognize it early, proactively prevent it, and handle it effectively, Vemedim provides detailed information on the causes, signs, and scientific treatment measures in the content below.
Causes of fish with raised scales
Fish with raised scales is a dangerous disease, often seen in fish raised in ponds, cement tanks, or cages. When infected, the fish’s abdomen swells, the scales stand up, and they may die in large numbers if not detected and treated in time.
This is not only a warning sign that the farming environment is deteriorating, but also indicates that the fish have suffered severe internal organ damage. This disease is not caused by a single factor, but is the result of multiple combined agents—from the environment and nutrition to pathogens.
Intestinal and internal organ bacterial infection
Bacteria such as Aeromonas hydrophila and Pseudomonas sp. are often the main causes. They attack the liver, kidneys, and intestines, causing blood vessel damage and fluid accumulation in the abdominal cavity. As pressure inside the body increases, the fish scales are pushed outward—creating the characteristic appearance of the disease.
>> See also:
- Gill rot disease in fish – Causes and effective treatment
- Anchor worm disease in fish – Symptoms and effective treatment
Parasites and fungi causing internal organ damage
Some blood parasites or water fungi (such as Saprolegnia sp.) destroy tissue and affect the fish’s ability to regulate salt and water balance. As a result, the fish develop edema, abdominal distension, and generalized raised scales.
Polluted farming environment
Pond water that accumulates a lot of organic matter and toxic gases such as NH₃ and H₂S, along with strong pH fluctuations, weakens fish health. When the immune system is weakened, fish are more susceptible to bacterial infection, especially during periods of erratic weather.
Nutritional deficiency or poor-quality feed
Spoiled feed, mold contamination, and deficiencies in vitamins A, D, C, and essential minerals reduce resistance, impair liver and kidney function, and create conditions for raised-scale disease to develop.
Signs of fish with raised scales
Early detection helps farmers intervene in time and minimize losses. Common signs include:
- The fish’s abdomen is enlarged, soft, and contains a lot of fluid.
- The scales stand up all over the body, and from above it looks like a pinecone.
- Bulging eyes, pale gills, sometimes turning gray.
- The fish swims sluggishly, loses balance, and stays near the water surface.
- Reduced feeding or complete loss of appetite.
- Some fish show mild hemorrhaging around the scale bases and anus.
How to prevent and treat raised-scale disease in fish
Raised-scale disease is considered one of the most difficult diseases to treat in farmed fish. Once the internal organs, especially the liver and kidneys, are damaged, recovery is almost impossible. If treatment is delayed, the mortality rate can reach 70–90%, especially in tilapia, grass carp, common carp, or pangasius.
Therefore, instead of relying on medication, proactive prevention is the sustainable solution to protect fish stocks and reduce losses.
Maintain a stable water environment
- Regularly change water, remove bottom sludge, and eliminate leftover feed.
- Maintain pH at 7–8 and a stable temperature of 26–30°C.
- Periodically treat ponds with probiotics or disinfectant solutions such as Vemedim Anti Parasite or Vemedim Bitech Yucca, Vemedim Bkc 80%, Vemedim Disina to reduce toxic gases and pathogens.
- Supplement probiotics such as Vemedim Vime Bitech Yucca, Vemedim Vime Subtyl, Vemedim Vime Bitech to help balance the pond microbiota and maintain long-term water quality.
Proper nutrition – boost fish resistance
- Feed high-quality feed and store it in a dry place to avoid mold and spoilage.
- Periodically mix vitamin C, digestive enzymes, and mineral supplements such as Vemedim ADE B.complex, Vemedim ANTI – SHOCK, Vemedim GLUSOME 115 into the daily ration.
- Add biological immunity-boosting products to help fish stay healthy, reduce stress, and resist disease-causing agents.
Prevention with safe antibiotics
- Use broad-spectrum antibiotics or antibacterial herbal products mixed according to veterinary instructions, especially during seasonal transitions.
- When bacterial infection is suspected, Doxycycline or Oxytetracycline may be mixed at the recommended dose, combined with vitamins to restore liver and kidney function.
Actions when disease is detected
- Immediately isolate the sick fish stock.
- Stop feeding for 1–2 days, and apply Iodine 90 (5–10 ml/m³ of water) to kill bacteria in the pond.
- After 6–8 hours, replace 30–50% of the water, combined with liming using CaCO₃ (10 g/m³) to stabilize the environment.
- Mix antibiotics and digestive enzymes into the feed for healthy fish continuously for 5–7 days.
- Closely monitor the fish stock’s health and avoid water shock or sudden water changes.
Raised-scale disease in fish is not only an aesthetic issue but also a clear sign that the environment, feed, or fish health is facing serious problems. Implementing synchronized measures for clean water management, selecting healthy stock, and strengthening resistance will be an important “shield” to prevent recurrence. With scientific solutions and the support of Vemedim, farmers can be more confident in managing their fish stock, aiming for a safe, efficient, and sustainable crop. Contact Vemedim now if you need detailed support!
