# Florfenicol for Animals: Mechanism, Doses by Species & Brands

> Florfenicol is a phenicol antibiotic used in cattle at 20 mg/kg IM repeated after 48 hours, or 40 mg/kg SC once. Some products combine it with an NSAID for respiratory disease with…

- Source page: https://wevet.in/active-ingredients/florfenicol/
- Type: Active ingredient
- Publisher: WeVet
- Updated: 2026-11-02
- Medically reviewed by: Dr. Ravi Baraiya, B.V.Sc. (2026-11-02)
- Audience: veterinarians and veterinary students

Florfenicol is a phenicol antibiotic used in cattle at 20 mg/kg IM repeated after 48 hours, or 40 mg/kg SC once [1]. Some products combine it with an NSAID for respiratory disease with fever — Resflor Gold with flunixin [2] and Zeleris with meloxicam [3].

- Class: Antibiotic (phenicol)
- Brands: Resflor Gold, Zeleris

## Dose by species

| Species | Use | Dose | Route | How often | Basis |
|---|---|---|---|---|---|
| Cattle | Respiratory disease (IM) | 20 mg/kg [1] | IM | Repeat once after 48 hours | Reference |
| Cattle | Respiratory disease (SC) | 40 mg/kg [1] | SC | Once | Reference |

## Uses

- Cattle (not veal or lactating dairy cows): bovine respiratory disease [1][2][3].

## Safety

- Not approved in dairy cattle 20 months of age or older [1].


## Frequently asked questions

### What is florfenicol combined with?

Resflor Gold combines it with flunixin [2]; Zeleris combines it with meloxicam [3].

## References

[1] Dosages of Chloramphenicol and Florfenicol — Merck Veterinary Manual (table) (2024). https://www.merckvetmanual.com/multimedia/table/dosages-of-chloramphenicol-and-florfenicol
[2] RESFLOR GOLD — label — Drugs.com Vet — US label text, Merck Animal Health (2026). https://drugs.com/vet/resflor-gold.html
[3] ZELERIS — Canadian label — Drugs.com Vet — Canadian label text, Ceva (2026). https://www.drugs.com/vet/zeleris-can.html

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Numbers in [brackets] cite the references above. For veterinary professionals. Information supports — never replaces — clinical judgement; always check the current product label and local regulations.
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