Fish · Cyprinus carpio · typical adult weight 0.25–20.00 kg
Metronidazole is dosed at 25 mg/l by immersion q48h in koi, per Ramsey I, ed. BSAVA Small Animal Formulary, 10th ed. Part B: Exotic Pets. Gloucester: British Small Animal Veterinary Association; 2023. p.217. — LOCATOR CONVENTION 2026-08-07: the bare 'p.217' in this citation is the PDF index of the held scan, not the printed page. The PRINTED page is p.203; verified by finding the drug named there. If you are holding the book, turn to p.203. — SOURCE EDITION: BSAVA Small Animal Formulary, Part B — Exotic Pets — ISBN 9781910443712, https://openlibrary.org/isbn/9781910443712. Metronidazole (Antibiotic) has cited veterinary dosing for koi. Routes documented in koi: by immersion, p.o.. A typical adult koi weighs 0.25–20.00 kg. ExoticRx lists 2 cited dose rules for Metronidazole in koi, drawn from published veterinary references. Verify against current literature before clinical use.
US trade names: Flagyl
| Route | Dose | Frequency | Indication | Evidence | Source |
|---|---|---|---|---|---|
| by immersion | 25 mg/l | q48h | — | Moderate | Ramsey I, ed. BSAVA Small Animal Formulary, 10th ed. Part B: Exotic Pets. Gloucester: British Small Animal Veterinary Association; 2023. p.217. — LOCATOR CONVENTION 2026-08-07: the bare 'p.217' in this citation is the PDF index of the held scan, not the printed page. The PRINTED page is p.203; verified by finding the drug named there. If you are holding the book, turn to p.203. — SOURCE EDITION: BSAVA Small Animal Formulary, Part B — Exotic Pets — ISBN 9781910443712, https://openlibrary.org/isbn/9781910443712Compilation only — we have not located an independent source that prints this figure. |
| p.o. | 100 mg/kg | q24h | — | Moderate | Ramsey I, ed. BSAVA Small Animal Formulary, 10th ed. Part B: Exotic Pets. Gloucester: British Small Animal Veterinary Association; 2023. p.217. — LOCATOR CONVENTION 2026-08-07: the bare 'p.217' in this citation is the PDF index of the held scan, not the printed page. The PRINTED page is p.203; verified by finding the drug named there. If you are holding the book, turn to p.203. — SOURCE EDITION: BSAVA Small Animal Formulary, Part B — Exotic Pets — ISBN 9781910443712, https://openlibrary.org/isbn/9781910443712Compilation only — we have not located an independent source that prints this figure. |
Every held source for this drug and species, as printed. Where they differ, both are shown — the choice is yours, not ours.
The sources disagree for this combination. The ranges below do not overlap on a comparable route. This is not an error in one of them — published veterinary references differ, and reconciling them for a particular patient is a clinical judgement.
| Dose (mg/kg) | Route | Source | As printed |
|---|---|---|---|
| 100 | PO | BSAVA Small Animal Formulary, 10th ed — Part B (Exotic Pets)p.217 | 25 mg/l by immersion q48h for 3 doses or 100 mg/kg p.o. q24h for 3 days. |
| 25 | PO | Carpenter's Exotic Animal Formulary, 6th edTable 2.2 | 25 mg/kg PO via feed q24h × 5-10 days |
| 50 | PO | Carpenter's Exotic Animal Formulary, 6th edTable 2.2 | 50 mg/kg PO via feed q24h × 5 days |
| 100 | PO |
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These ranges are per kg. Enter your koi's weight to get the precise dose and draw-up volume — unit and concentration math done for you.
Disrupts DNA structure in anaerobic organisms via reduction of nitro group, forming cytotoxic intermediates.
Neurotoxicity at high doses or prolonged use (ataxia, seizures). Avoid in pregnant animals. Hepatotoxic at high doses.
Species-specific contraindications and adverse-reaction reports for koi may differ from canine / feline reference data — consult the primary citations listed with each rule.
Metronidazole dose ranges in koi, with cited source references: by immersion 25 mg/l q48h; p.o. 100 mg/kg q24h. Reference ranges from cited sources — verify against current literature before clinical use.
Documented routes for Metronidazole in koi: by immersion, p.o..
These are general warnings for Metronidazole across species; consult the koi dosing table above for species-specific guidance. Neurotoxicity at high doses or prolonged use (ataxia, seizures). Avoid in pregnant animals. Hepatotoxic at high doses.
Why a species-specific page? Metronidazole pharmacokinetics differ across species: dose ranges, intervals, and route preferences are not interchangeable. Cross-extrapolation from canine doses is unsafe in koi — the rules above are the citations specific to this species, not generic recommendations.
Sourced from published veterinary references; awaiting credentialed clinical reviewer. See our editorial process. Reference only — not veterinary advice.
| Carpenter's Exotic Animal Formulary, 6th edTable 2.2 |
| 100 mg/kg PO via feed q24h × 3 days 6.25-18 mg/g of feed × 5 days Bioencapsulation of metronidazole in brine shrimp |
| Dose (mg/l) | Route | Source | As printed |
|---|---|---|---|
| 25 | IMMERSION | BSAVA Small Animal Formulary, 10th ed — Part B (Exotic Pets)p.217 | 25 mg/l by immersion q48h for 3 doses or 100 mg/kg p.o. q24h for 3 days. |
| 25 | IMMERSION | Carpenter's Exotic Animal Formulary, 6th edTable 2.2 | - 6.6 mg/L bath q24h × 3 days 25 mg/L bath q48h × 3 treatments |
| 6.6 | IMMERSION | Carpenter's Exotic Animal Formulary, 6th edTable 2.2 | - 6.6 mg/L bath q24h × 3 days 25 mg/L bath q48h × 3 treatments |
Figures are transcribed from the cited page or table of each held edition and are shown for reference only. They are not dose recommendations, they do not feed the calculator, and none has been reviewed by a veterinarian.