# Cefotaxime: veterinary dose and monograph

> Cefotaxime is a veterinary antibiotic. Third-generation cephalosporin with broad Gram-negative cover and good Gram-positive activity, and importantly good CNS (CSF) penetration — making it a strong choice for sepsis, meningitis and neonatal infections (e.g. Indications include sepsis / bacteraemia (broad empiric cover pending culture); bacterial meningitis / CNS infection (CSF penetration); neonatal sepsis (foals, pups). This monograph lists 5 reference doses for dogs, cats, horses, birds and reptiles, each with route, frequency and source.

Source: https://vetmasterji.com/drugs/cefotaxime · Last reviewed: 2026-10-01

## At a glance

- **Drug class:** Antibiotic
- **Also known as:** Claforan, Taxim, Omnatax
- **Species with doses:** Dogs, Cats, Horses, Birds and Reptiles
- **General dose range:** 20–40 mg/kg IV q6–8h — check the species tables for the indication
- **Routes:** IV, IM
- **Last reviewed:** 1 October 2026

## Indications

- Sepsis / bacteraemia (broad empiric cover pending culture)
- Bacterial meningitis / CNS infection (CSF penetration)
- Neonatal sepsis (foals, pups)
- Serious soft-tissue, respiratory and urinary infections

## Cefotaxime dose by species

Doses are per administration unless stated. mg/kg doses scale with body weight; per-animal, per-quarter and infusion-rate doses are shown as the reference writes them.

### Dogs

*Cefotaxime doses for dogs*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Serious susceptible infection / sepsis | 20–40 mg/kg | IV | q6–8h | — |

- Serious susceptible infection / sepsis: Papich 5e: 25 mg/kg q8h IV, IM or SC; CRI 3.2 mg/kg load then 5 mg/kg/h. Plumb’s p.216: 25–50 mg/kg IV, IM or SC q8h (Vaden & Papich); orthopaedic 20–40 mg/kg q6–8h; severe bacteraemia 20–80 mg/kg IV q6h; CNS 25–50 mg/kg q8h (Dickinson 2003).

### Cats

*Cefotaxime doses for cats*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Serious susceptible infection | 25–50 mg/kg | IV | q8h | — |

- Serious susceptible infection: Papich 5e: 25 mg/kg q8h IV, IM or SC. Plumb’s p.216: 25–50 mg/kg IV, IM or SC q8h (Vaden & Papich; Lappin); severe bacteraemia 20–80 mg/kg q6h; severe pancreatitis 50 mg/kg IM q8h (Zoran 2008).

### Horses

*Cefotaxime doses for horses*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Foal sepsis / meningitis | 25–40 mg/kg | IV | q6h | — |

- Foal sepsis / meningitis: Papich 5e: foals 40 mg/kg q6h IV over 1 min, or CRI 4 mg/kg load then 2.5 mg/kg/h; adult horses 25 mg/kg q6h IV. Plumb’s p.216: foals 40 mg/kg IV q6h (Giguere); meningitis 40 mg/kg IV 3–4 times daily (Furr); 20–30 mg/kg IV or IM q6–8h. Good CSF penetration.

### Birds

*Cefotaxime doses for birds*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Systemic infection | 50–100 mg/kg | IM | q8h | — |

- Systemic infection: Plumb’s p.216: most birds 50–100 mg/kg IM three times daily (Clubb 1986); 75–100 mg/kg IM or IV q4–8h (Oglesbee; Hess); 75 mg/kg IM q8h (Tully). Ratites 25 mg/kg IM three times daily.

### Reptiles

*Cefotaxime doses for reptiles*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Susceptible infection | 20–40 mg/kg | IM | q24h | 7–14 days |

- Susceptible infection: Plumb’s p.216: 20–40 mg/kg IM once daily for 7–14 days (Gauvin 1993); chelonians 20–40 mg/kg IM q24h (Johnson 2002).

## Contraindications

Beta-lactam hypersensitivity. Reduce in significant renal impairment. Reserve for serious/resistant infection (stewardship). Known hypersensitivity.

## Species-specific warnings

> **Caution:** Horses: Widely used for neonatal foal sepsis/meningitis; frequent dosing required.

## Adverse effects

- Injection-site pain/phlebitis
- GI upset, diarrhoea
- Hypersensitivity reactions
- Rare neutropenia/thrombocytopenia on prolonged use

## Drug interactions

- Aminoglycosides: synergy (Gram-negative) but additive nephrotoxicity and physical incompatibility
- Other nephrotoxins: additive renal risk
- Probenecid: prolongs half-life
- Bacteriostatic agents: possible antagonism

## Pregnancy and lactation

Considered safe in pregnancy/lactation (cephalosporin class); used in neonates.

## Monitoring

- Culture & sensitivity; clinical response
- Renal function on prolonged/high-dose use
- CBC if therapy exceeds ~2 weeks
- Hypersensitivity at first dose

## Toxicity and overdose

Wide margin; main risks are hypersensitivity and, with prolonged use, reversible haematologic effects. Accumulates in renal failure.

Management: Supportive; no specific antidote. Treat hypersensitivity/anaphylaxis conventionally. Fluids and dose reduction in renal impairment.

## Clinical pearls

- A go-to broad-spectrum cephalosporin for sepsis and the rare CNS infection thanks to CSF penetration
- Short half-life — dose q6–8h or it under-performs
- Excellent first empiric choice in neonatal foal sepsis pending culture
- Reserve third-generation cephalosporins for serious infection to slow resistance

## Mechanism of action

Binds penicillin-binding proteins to inhibit bacterial cell-wall synthesis (bactericidal, time-dependent). Its third-generation structure resists many Gram-negative beta-lactamases and penetrates the inflamed blood–brain barrier, giving therapeutic CSF concentrations — the basis of its use in meningitis/sepsis. The active metabolite desacetylcefotaxime contributes additional activity.

## Formulations and products

- Cefotaxime 1 g dry-powder vial — reconstitute per label (no reconstituted mg/mL in Papich 5e or Plumb’s)
- Taxim — 250 mg / 500 mg / 1 g vial, Injection (human-label)
- Omnatax / Claforan — 1 g vial, Injection (human-label)

## Storage

Powder vial: 15–25 °C, protect from light. Reconstituted: refrigerate, use within 24 h (may darken slightly — still usable per label).

## Before you use this dose

> **Caution:** Reference doses for veterinary professionals. Confirm the dose against the product label, the patient’s condition, current guidance and local regulations before use; the attending veterinarian remains responsible for every clinical decision.

## Other antibiotics

- [Cefadroxil](https://vetmasterji.com/drugs/cefadroxil)
- [Cefazolin](https://vetmasterji.com/drugs/cefazolin)
- [Cefixime](https://vetmasterji.com/drugs/cefixime)
- [Cefoperazone](https://vetmasterji.com/drugs/cefoperazone)
- [Cefovecin](https://vetmasterji.com/drugs/cefovecin)
- [Cefpodoxime proxetil](https://vetmasterji.com/drugs/cefpodoxime)
- [Cefquinome](https://vetmasterji.com/drugs/cefquinome)
- [Ceftazidime](https://vetmasterji.com/drugs/ceftazidime)

## Frequently asked questions

### What is the dose of Cefotaxime for dogs?

Reference doses for Cefotaxime in dogs: 20–40 mg/kg IV q6–8h (Serious susceptible infection / sepsis). Confirm against the label and the patient before use.

### What is the dose of Cefotaxime for cats?

Reference doses for Cefotaxime in cats: 25–50 mg/kg IV q8h (Serious susceptible infection). Confirm against the label and the patient before use.

### What is the dose of Cefotaxime for horses?

Reference doses for Cefotaxime in horses: 25–40 mg/kg IV q6h (Foal sepsis / meningitis). Confirm against the label and the patient before use.

### When should Cefotaxime not be used?

Beta-lactam hypersensitivity. Reduce in significant renal impairment. Reserve for serious/resistant infection (stewardship). Known hypersensitivity.

### What are the side effects of Cefotaxime in animals?

Injection-site pain/phlebitis; GI upset, diarrhoea; Hypersensitivity reactions; Rare neutropenia/thrombocytopenia on prolonged use.

## Sources

- Plumb's Veterinary Drug Handbook
- Merck Veterinary Manual, 11th edition
- Papich, Papich Handbook of Veterinary Drugs, 5th edition

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VetMasterJi is a clinical decision-support and education platform for veterinary professionals and students. It does not provide veterinary advice, diagnosis or treatment for specific animals. All drug doses, calculators and differentials are references that must be independently verified before clinical use; the attending registered veterinarian remains solely responsible for every clinical decision.