Vancomycin: veterinary dose and monograph

At a glance

Drug class

Antibiotic

Also known as

Vancocin, Vancomab, Vanlid

Species with doses

Dogs, Cats and Horses

General dose range

15 mg/kg IV q6–8h — check the species tables for the indication

Routes

IV, PO

Last reviewed

1 October 2026

Indications

• Methicillin-resistant Staphylococcus (MRSA/MRSP) infection with no other option
• Resistant enterococcal infection
• Serious resistant Gram-positive sepsis (culture-confirmed)
• Oral: refractory C. difficile / antibiotic-associated colitis (gut-local)

Vancomycin 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

• Resistant Gram-positive infection (IV): Papich 5e: 15 mg/kg q6–8h IV infusion (start q8h, shorten to q6h by monitoring). Plumb’s p.1160: bacteraemia 15 mg/kg IV over 30–60 min q6–8h (Ford 2005); skin/urinary/soft tissue 10–20 mg/kg IV q12h for 7–10 days (Greene). Dilute (≥100 mL per 500 mg); reserve for MRSA/MRSP and resistant enterococci.
• Refractory C. difficile colitis (oral, gut-local): Plumb’s p.1160 (Greene 2006): C. difficile enterocolitis 10–20 mg/kg PO q6h for 5–7 days. Not absorbed orally — gut lumen only.
• Constant-rate infusion: Papich 5e: loading dose 3.5 mg/kg, then 1.5 mg/kg/h in 5% dextrose.

Cats

• Resistant Gram-positive infection (IV): Papich 5e: 12–15 mg/kg q8h IV infusion. Plumb’s p.1160: 15 mg/kg IV over 30–60 min q6–8h (Ford 2005; Papich 2003 — combine with an aminoglycoside for serious infections). Reserve for confirmed resistant enterococci/staphylococci; monitor renal function and trough levels.

Horses

• Resistant Gram-positive infection: Papich 5e: 4.3–7.5 mg/kg q8h IV over 1 hour; regional limb perfusion 300 mg as a 0.5% solution.

Contraindications

Rapid IV infusion (causes "red man" syndrome — histamine-mediated flushing/hypotension; infuse over ≥60 min). Renal impairment (nephrotoxic — adjust by levels). Concurrent nephro-/ototoxins. Routine use (reserve agent). Known hypersensitivity.

Adverse effects

• "Red man" syndrome (flushing, hypotension) with rapid infusion
• Nephrotoxicity (dose/level-related)
• Ototoxicity (high levels, prolonged use)
• Phlebitis, fever, neutropenia (prolonged use)

Drug interactions

• Aminoglycosides / amphotericin B / other nephrotoxins: additive nephro-/ototoxicity
• Anaesthetics: increased frequency of red-man-type reactions
• Neuromuscular blockers: enhanced blockade

Pregnancy and lactation

Limited veterinary data; reserved for life-threatening resistant infection where benefit outweighs risk.

Monitoring

• Serum trough levels (therapeutic drug monitoring) where available
• Renal function (creatinine) frequently
• Infusion rate / red-man reaction
• Hearing (prolonged therapy); culture confirming a no-alternative resistant organism

Toxicity and overdose

Dose-/level-dependent nephrotoxicity and ototoxicity are the key toxicities; rapid infusion provokes red-man syndrome (flushing, hypotension). Therapeutic drug monitoring (trough levels) is ideal to balance efficacy and toxicity.

Management: No specific antidote. Slow/stop the infusion for red-man syndrome and give antihistamine ± fluids. For toxicity: discontinue, support renal function with fluids, monitor hearing/renal values; some removal by high-flux haemodialysis/haemofiltration.

Clinical pearls

• Reserve of last resort — only for culture-confirmed MRSA/MRSP or resistant enterococci with NO alternative (One-Health stewardship)
• Infuse slowly (≥1 h): fast IV causes red-man syndrome (flushing, hypotension)
• IV for systemic infection; ORAL vancomycin treats only gut C. difficile (it is not absorbed)
• Monitor renal function and, ideally, trough levels to stay effective without toxicity
• Never use casually — veterinary vancomycin use is ethically and epidemiologically sensitive

Mechanism of action

Binds the D-alanyl-D-alanine terminus of peptidoglycan precursors, sterically blocking transglycosylation/transpeptidation and halting bacterial cell-wall synthesis — bactericidal against Gram-positives (its large molecule cannot cross the Gram-negative outer membrane, hence no Gram-negative activity). Resistance (e.g. VRE) arises from altered D-Ala-D-Lac termini.

Formulations and products

• Injection 500 mg vial (reconstitute)
• Injection 1 g vial (reconstitute)
• Vancocin — 500 mg / 1 g vial, Injection (reconstitute) (human-label)
• Vanlid — 250 mg capsule; 500 mg / 1 g vial, Capsule / injection (human-label)

Storage

Powder vial: 15–30 °C. Reconstituted/diluted solution: refrigerate and use within ~24 h (per label). Infuse diluted (never as a bolus).

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

• Tobramycin
• Trimethoprim / Sulfadiazine (TMP-Sulfa)
• Tulathromycin
• Tylvalosin

Frequently asked questions