Cefotaxime: veterinary dose and monograph

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

• 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

• 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

• 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

• 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

• 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

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

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
• Cefazolin
• Cefixime
• Cefoperazone
• Cefovecin
• Cefpodoxime proxetil
• Cefquinome
• Ceftazidime

Frequently asked questions