Protocol QT-01

Bacillary necrosis

This one cannot be judged from the outside. Open 5–10 fish to see the white pus spots on liver, kidney and spleen — the only reliable sign.

AgentEdwardsiella ictaluri

SpeciesPangasius · snakehead · climbing perch · catfish

Withdrawal4 weeks before harvest

Step 0 · Identify

What you see at the pond

No antibiogram needed. But this disease requires opening fish — the external signs overlap with several others.

Sluggish, leaving the school, off feed
Scattered deaths rising fast over a few days
On necropsy: fine white pus spots on liver, kidney, spleen

Treatment

Day by day

Environment first, medicine after. The chart below includes the withdrawal period.

1
Stop feeding, change 30% of the waterDay 1
Stop feeding entirely. Siphon the bottom if the pond allows.
2
Disinfect the waterDay 1
VIBRIO CLEAR1 kg / 3,000 m³
Than Vuong product, currently catalogued under the snail line — to be moved to the fish line.
3
Second disinfectionDay 2–4
KMnO₄ + salt1 kg/1,500 m³ + 10 kg/1,000 m³
Common farm input, not a Than Vuong product.
4
Antibiotic — resume feeding at a low rateDay 1–10
FLOR-MAX + DOXYPA1 L each per 600–1,000 kg feed · once daily (fish under 2 months: 1 L per 1,000–1,400 kg feed)
5
Cut the pathogen loadDay 12
FYTOBLOOM PLUS1 L / 1,500 m³
Not yet in the web catalogue. Substitute AQUA DINE New 1 bottle/2,000–2,500 m³.
6
Liver recovery, raise feed graduallyDay 11–14
CANFORTA · HERB GUARD · QUICKSHELL GOLD1 L/800 kg + 1 L/1,000 kg + 1 L/1,000 kg feed

Withdrawal

4 weeks

From the last dose. FLOR-MAX needs 12 days, DOXYPA 4 weeks — combined, take the longer one.

No improvement in 3–5 days

Stop dosing, do not raise the dose. Open 5–10 more fish to check for co-infection with haemorrhage. Check toxic gases and the pond bottom. Call Than Vuong technical staff before a second course.

Note

Remove dead fish from the pond every day to limit spread.

Products used