Cefquinome: veterinary dose and monograph

At a glance

Drug class

Antibiotic

Also known as

Cobactan, Cobactan LC, Bactivon

Species with doses

Cattle, Horses and Pigs

General dose range

1–2 mg/kg IM q24h — check the species tables for the indication

Routes

IM, Intramammary, IV

Last reviewed

1 October 2026

Indications

• Bovine respiratory disease (Pasteurella multocida, Mannheimia haemolytica)
• Digital dermatitis, infectious bulbar necrosis, acute interdigital necrobacillosis
• Acute E. coli mastitis with systemic involvement
• Calf E. coli septicaemia
• Sheep/goat bacterial septicaemia, pneumonia, GI infection
• Swine MMA syndrome, respiratory disease, meningitis, arthritis
• Equine respiratory disease (Streptococcus equi)

Cefquinome 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.

Cattle

• Respiratory disease / digital dermatitis (Cobactan 2.5 %): Papich 5e (EU label): respiratory disease and foot rot 1 mg/kg (2 mL per 50 kg of the 2.5% suspension) IM once daily for 3–5 days; BRD 2.5 mg/kg IM q48h with the 7.5% product. Label withdrawal (2.5% product, EU) about 5 days meat and 24 h milk — confirm the local label. Plumb’s 10e p.218: cattle 1 mg/kg IM once daily for 2 to 5 consecutive days depending on indication and age; neck injection site, rotating subsequent sites (extra-label use is prohibited in the US).
• Acute E. coli mastitis (systemic, Cobactan 2.5 %): Papich 5e (EU label): mastitis with systemic involvement 1 mg/kg (2 mL/50 kg of 2.5% suspension) IM once daily for 2 days.
• Clinical mastitis — intramammary (Cobactan LC): Label-sourced — one 75 mg syringe per affected quarter after each of three consecutive milkings (q12h). Not dosed in Papich 5e; Plumb’s 10e cefquinome monograph (pp.216–218) gives injectable doses only, no intramammary regimen. Follow the local product label for meat and milk withdrawals.
• Calf E. coli septicaemia: Papich 5e (EU label): E. coli septicaemia in calves 2 mg/kg (4 mL per 50 kg of the 2.5% suspension) IM once daily for 3–5 days. Follow the local label withdrawal.

Horses

• Streptococcus equi respiratory infection: Papich 5e (EU label): respiratory infection caused by S. equi 1 mg/kg IV or IM q24h for 5–10 days.
• Foal E. coli septicaemia: Papich 5e (EU label): systemic infection, especially E. coli septicaemia in foals, 1 mg/kg IV or IM q12h for 6–14 days.

Goats

• No reference dose for this species: The previous 2 mg/kg IM goat row had no source; Papich 5e gives cefquinome doses only for cattle, pigs, horses, dogs and cats, and Plumb’s 10e (pp.216–218) only for horses, cattle and pigs.

Sheep

• No reference dose for this species: The previous 2 mg/kg IM sheep row had no source; Papich 5e gives cefquinome doses only for cattle, pigs, horses, dogs and cats, and Plumb’s 10e (pp.216–218) only for horses, cattle and pigs.

Pigs

• MMA / respiratory / arthritis / meningitis: Papich 5e (EU label): respiratory infections 2 mg/kg IM in the neck once daily for 2 days; meningitis, arthritis or dermatitis in piglets 2 mg/kg IM once daily for 5 days.

Buffalo

No buffalo-specific doses are on file, so buffalo are dosed as cattle.

• Respiratory disease / digital dermatitis (Cobactan 2.5 %): Papich 5e (EU label): respiratory disease and foot rot 1 mg/kg (2 mL per 50 kg of the 2.5% suspension) IM once daily for 3–5 days; BRD 2.5 mg/kg IM q48h with the 7.5% product. Label withdrawal (2.5% product, EU) about 5 days meat and 24 h milk — confirm the local label. Plumb’s 10e p.218: cattle 1 mg/kg IM once daily for 2 to 5 consecutive days depending on indication and age; neck injection site, rotating subsequent sites (extra-label use is prohibited in the US).
• Acute E. coli mastitis (systemic, Cobactan 2.5 %): Papich 5e (EU label): mastitis with systemic involvement 1 mg/kg (2 mL/50 kg of 2.5% suspension) IM once daily for 2 days.
• Clinical mastitis — intramammary (Cobactan LC): Label-sourced — one 75 mg syringe per affected quarter after each of three consecutive milkings (q12h). Not dosed in Papich 5e; Plumb’s 10e cefquinome monograph (pp.216–218) gives injectable doses only, no intramammary regimen. Follow the local product label for meat and milk withdrawals.
• Calf E. coli septicaemia: Papich 5e (EU label): E. coli septicaemia in calves 2 mg/kg (4 mL per 50 kg of the 2.5% suspension) IM once daily for 3–5 days. Follow the local label withdrawal.

Contraindications

Cephalosporin hypersensitivity. Severe renal failure. Not for use in calves intended for veal production. Withdrawal must be respected — see label.

Species-specific warnings

Cattle: Approved for BRD, mastitis, metritis at 1 mg/kg IM q24h. Cobactan LC intramammary 24 h milk / 5 d slaughter withdrawal (shortest in class).

Goats: 2 mg/kg IM q24h (extra-label). Faster clearance than cattle.

Sheep: 2 mg/kg IM q24h (extra-label).

Pigs: 2 mg/kg IM q24h × 3–5 days. Approved for swine respiratory and arthritis.

Horses: 1 mg/kg IM q24h × 3–5 days. IM only — never IV. Risk of injection-site myopathy in some horses.

Rabbits: Avoid — fatal clostridial enterotoxaemia.

Adverse effects

• Local injection-site reaction
• Hypersensitivity / urticaria (rare)
• Transient inflammation at intramammary infusion site

Drug interactions

• Aminoglycosides: synergistic against Gram-negatives but additive nephrotoxicity in dehydrated patients
• NSAIDs / loop diuretics: additive nephrotoxicity risk
• Penicillins: cross-reactivity for hypersensitivity (~10%)
• Other cephalosporins: cross-reactivity for hypersensitivity
• Probenecid: prolongs cefquinome half-life
• Calcium-containing IV fluids: do NOT co-infuse (precipitation risk)

Pregnancy and lactation

Safe in pregnant cattle, pigs, mares at label doses. Excreted in milk in low concentrations. Widely used in dairy cattle for mastitis (Cobactan LC intramammary). FDA Category B (human extrapolation).

Monitoring

• Withdrawal periods strictly: cattle 5 d slaughter / 24 h milk (Cobactan parenteral); 4 d milk discard (Cobactan LC intramammary)
• Injection-site swelling / discoloration — rotate sites
• Hypersensitivity signs especially first dose
• Renal function on prolonged courses or in dehydrated patients
• Use restraint — broad-spectrum 4th-gen ceph; reserve for documented resistant infections, not first-line

Toxicity and overdose

Wide therapeutic margin. Acute toxicity rare. Injection-site reaction (transient swelling, discomfort). Hypersensitivity (urticaria, rare anaphylaxis). Some reports of injection-site myopathy in horses — IM only. No significant nephro / hepato / haematologic toxicity at label doses. Discoloration of muscle at injection site (trim loss in food animals).

Management: No specific antidote. Supportive: IV fluids, anti-emetic. Anaphylaxis standard protocol (epinephrine, antihistamine, corticosteroid). Injection-site reaction: NSAID + cold compress.

Clinical pearls

• Bovine respiratory disease (BRD) / metritis / foot rot: 1 mg/kg IM q24h × 3–5 days — Cobactan / Bactivon standard in Indian dairy
• Bovine clinical mastitis (Cobactan LC): 75 mg per quarter q12h × 3 milkings — strict 24 h milk / 5 d slaughter withdrawal
• Swine / sheep / goat: 2 mg/kg IM q24h (higher than cattle due to faster clearance)
• Equine strangles: 1 mg/kg IM q24h × 3–5 days
• RESERVE for documented Gram-negative resistance — 4th-gen overuse drives ESBL emergence
• Cobactan LC mastitis: shortest milk discard (24 h) of any major intramammary 4th-gen ceph

Mechanism of action

Fourth-generation cephalosporin (veterinary-only — not used in human medicine). Zwitterionic structure penetrates Gram-negative outer membrane more effectively than 3rd-gen cephs. Binds penicillin-binding proteins (PBPs); inhibits peptidoglycan cross-linking. Bactericidal, time-dependent. Stable against most beta-lactamases including AmpC and many ESBLs. Broad spectrum: Gram-positive cocci (incl. beta-lactamase-producing Staphylococcus), most Gram-negatives including Pseudomonas (limited), respiratory pathogens (Mannheimia, Pasteurella, Histophilus, Mycoplasma).

Formulations and products

• Cobactan 2.5 % suspension 25 mg/mL (MSD)
• Cobactan LC intramammary 75 mg per syringe (MSD — label-sourced)
• Bactivon 500 mg vial + 15 mL solvent → 33.3 mg/mL (Intas)
• Cobactan 2.5 % (MSD Animal Health) — 25 mg/mL, Injectable suspension
• Cobactan LC (MSD Animal Health) — 75 mg per syringe, Intramammary syringe
• Bactivon (Intas (Neovet)) — 500 mg, Vial + 15 mL solvent

Storage

Cobactan 2.5%: 15–25 °C, do NOT freeze. Shake well before use. Multidose vial: 28 days after broaching. Cobactan LC intramammary: 15–25 °C. Bactivon vial + WFI: 15–25 °C, use reconstituted within 24 h.

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.

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Frequently asked questions