From May to August every year, the three words that Pelteobagrus fulvidraco farmers fear hearing the most are - ascites disease!
This disease, known as the "fishpond plague", can cause the mortality rate of fish to soar to 80%, and even lead to the total destruction of the entire pond!
Today, we delve into the core causes of ascites and practical prevention and treatment plans to keep your Pelteobagrus fulvidraco away from a "big belly"!
I. Symptom Manifestations
Typical symptoms of diseased fish:
Swollen abdomen (like an inflated balloon)
The anus is red, swollen and turned outward (bleeding in severe cases).
Wandering alone and pacing around (slow to react)
Increased mucus on the body surface (feels extremely slippery and greasy)
Anatomical characteristics:
There is bloody fluid or yellow gel-like substance in the abdominal cavity (like jelly).
The liver is dull yellow and the spleen is necrotic (with severe damage to the liver and gallbladder).
No food in the intestines, pale stomach (digestive system collapse)
Ascites disease is often accompanied by parasitic infections (such as trichoderma and ringworm). If not treated in time, the mortality rate can exceed 80%
Ii. Causes of the Disease: The three main culprits leading to ascites
The water quality has deteriorated
Deterioration of the substrate: Accumulation of leftover feed and feces, excessive hydrogen sulfide and methane at the bottom, inducing bottom-dwelling stress.
Low dissolved oxygen (<3mg/L) leads to a decline in the immunity of fish.
Sudden weather changes (heavy rain, temperature drop) have caused sharp fluctuations in water quality.
2. Improper feeding
Excessive feeding: The accumulation of feed in the intestines leads to fermentation and gas production, resulting in enteritis and ascites.
Feed deterioration: Oil oxidation and excessive mycotoxins directly damage the liver and intestines.
Nutritional imbalance: Vitamin E deficiency, increased capillary permeability, and ascites exudation.
3. Drug abuse
The abuse of pesticides and disinfectants disrupts the balance of bacteria and algae in water bodies, causes stress in fish bodies, and leads to secondary infections.
Aeromonas hydrophila: Its reproduction rate doubles at water temperatures of 25-30℃, and it can penetrate the intestinal wall and enter the abdominal cavity within 24 hours.
Iii. Prevention and Control Plan: Three-Step "Life-Saving Rule"
Prevention Section: Water quality management is the key
Water level management: Maintain a water depth of ≥2 meters to reduce the stress caused by the temperature difference between day and night.
Regular bottom improvement: Use potassium peroxymonosulfate complex salt to improve the bottom every 10 days to decompose the organic matter at the bottom.
Dissolved oxygen guarantee: On sunny days, the aerator should be turned on for 2 hours at noon, and on cloudy or rainy days, it should be kept on all day to ensure that the dissolved oxygen is greater than 5mg/L.
Feeding Section: Precise feed control + Liver and Intestinal Protection
"Three-look" feeding method:
Check the weather: Stop feeding one day before heavy rain or temperature drop.
Check the water quality: When the ammonia nitrogen is greater than 0.2mg/L, reduce the feed by 50%.
Check the fish: Stop feeding immediately when the proportion of diseased fish exceeds 10%.
Functional feed addition: Mix bile acid (0.5kg/ ton of feed) + vitamin E (200g/ ton of feed) to repair liver and intestinal damage.
Feed Clostridium butyricum (100g per ton of feed) once every 15 days to regulate the balance of intestinal flora.
Therapeutic Section: Internal and external strikes for rapid hemostasis
Step 1: External disinfection + oxygenation: Apply povidone-iodine (1 mu · m/bottle) and granular oxygen (2kg/ mu) throughout the pond. After 24 hours, change 30% of the water.
Step 2: Administer oral antibiotics + liver-protecting drugs (10% content, 100g/10kg feed) + Sanhuang Powder (500g/10kg feed) + vitamin K3 (100g/10kg feed) for 5 consecutive days. Simultaneously mix and feed Ganlebao (500g/10kg feed) to enhance the liver's detoxification ability.
Step 3: Harmless treatment of dead fish. During the peak period of the disease, dead fish should be retrieved and buried deeply every day to prevent the spread of the pathogen.
Special reminder: Don't fall into these traps!
Error 1: Using irritating insecticides during the disease onset period doubles the death rate of fish due to stress.
Error Operation 2: Using antibiotics alone while neglecting liver and intestinal protection, resulting in a recurrence rate exceeding 60%.
Error 3: Frequent addition of fresh water during the high-temperature period causes a sudden drop in water temperature, triggering "bubble disease".