Florfenicol
Florfenicol is a broad-spectrum protein-synthesis inhibitor with established livestock respiratory uses and additional species-specific regimens.
Group
Amphenicol antibacterial
Mechanism of Action
Binds the bacterial 50S ribosomal subunit and inhibits protein synthesis.
Dose Rates
Cattle
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Bovine respiratory disease | 20 mg/kg | IM | Every 48 h | Two injections total, in the neck. Nuflor 300 mg/mL: maximum 10 mL per site. |
| Bovine respiratory disease | 40 mg/kg | SC | Once | Nuflor: maximum 10 mL/site; Nuflor Gold: maximum 15 mL/site, in the neck. |
Dogs
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Susceptible systemic infection | 20 mg/kg | IM | Every 8 h | Up to 5 days; Course 3-5 days; injection may be painful. |
Cats
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Susceptible systemic infection | 22 mg/kg | IM, PO | Every 12 h | Up to 5 days; Course 3-5 days. Oral use requires a suitable formulation, not automatic oral administration of any injection. |
Pigs
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Respiratory infection – drinking water | Reference only | PO | Up to 5 days; NuFlor concentrate water regimen: 100 mg/L as the only drinking water for 5 days. The source also approximates this as 400 mg/US gallon; base preparation on the stated metric concentration. |
Goats
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Respiratory disease in kids | Reference only | PO | Source describes 20 mg/kg daily for 2 days but does not establish the route; no parenteral route is inferred. |
Chickens
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Susceptible bacterial infection – drinking water | Reference only | PO | Up to 5 days; Fenlor 100 mg/mL: 1 mL per litre of drinking water for 3-5 days; prepare to actual daily water consumption. |
Indications
- Bovine respiratory disease
- Susceptible systemic infections
- Selected porcine and poultry bacterial infections
Contraindications
- Do not administer injectable products IV.
- Breeding-animal and lactating-dairy restrictions depend on formulation; cited Nuflor products exclude female dairy cattle 20 months or older and veal calves.
Interactions
- Other 50S-binding antibacterials may be antagonistic; clinical significance is uncertain.
Adverse effects
- Reduced appetite or water intake, diarrhoea and injection-site lesions.
- Rare hypersensitivity or collapse.
Toxicity
Overdose may amplify gastrointestinal effects and liver-enzyme changes; provide supportive care.
Preparations
| Preparation | Form | Strength | Route |
|---|---|---|---|
| NuFlor injection 300 mg/mL Protect from inappropriate heat; in-use period 28 days at 2-30°C. | Injection | 300 mg / mL | IM, SC |
| Fenlor oral solution 100 mg/mL Selmore Pharmaceuticals (Pvt) Ltd. Shake; use medicated water within 24 hours. Store at 15-25°C. Poultry meat withdrawal 7 days. | Oral Liquid | 100 mg / mL | PO |
Monitoring and Administration
Use the neck for cattle injections. Maximum site volume differs between Nuflor and Nuflor Gold.
Monitor clinical response and injection sites; investigate persistent fever or treatment failure.
Nuflor withdrawal: cattle meat 28 days after IM treatment, 38 days after SC; Nuflor Gold 44 days. These periods are product-specific.