Dipyrone (Metamizole): veterinary dose and monograph

At a glance

Drug class

Analgesic

Also known as

Vetalgin, Novalgin, Analgin

Species with doses

Dogs, Cats, Cattle, Horses, Goats, Sheep, Pigs and Buffalo

General dose range

25–50 mg/kg IV q24h prn — check the species tables for the indication

Routes

IV, IM

Last reviewed

1 October 2026

Indications

• Equine colic — visceral analgesia
• Cervical spasm at parturition / cervical insufficiency
• Post-operative analgesia (multimodal)
• Pyrexia (rapid antipyretic, especially IV)
• Smooth-muscle spasm pain (urethral obstruction, mild gut spasm)

Dipyrone (Metamizole) 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

• Pain / pyrexia (cautious): Papich 5e: dogs 50 mg/kg IV, IM or SC q12h. Product catalogue (500 mg/mL): 1–5 mL slow IV per dog. Safe doses are NOT established in cats (Papich). Avoid in dogs with a history of blood dyscrasia.
• Perioperative analgesia (Plumb’s 10e): Plumb’s 10e p.415 (extra-label): 25 mg/kg IV prior to or immediately following surgery. One study suggests dipyrone should not be the sole analgesic in the perioperative period. Inhibits platelet aggregation in dogs (p.414).

Cats

• Post-operative analgesia — q24h: Plumb’s 10e p.415 (extra-label): 25 mg/kg IV every 24 hours has been reported for post-operative analgesia; efficacy in cats is unclear (p.414). Reported adverse effects in cats: vomiting and salivation. REFERENCE CONFLICT: Papich 5e states safe doses are not established in cats.
• Post-operative analgesia — q12h: Plumb’s 10e p.415 (extra-label): 12.5 mg/kg IV every 12 hours has been reported for post-operative analgesia; efficacy unclear (p.414). REFERENCE CONFLICT: Papich 5e states safe doses are not established in cats.

Cattle

• Colic / post-op / pyrexia: Label-sourced (Vetalgin 500 mg/mL): 20–40 mL (10–20 g) per adult cow slowly IV (≈25–50 mg/kg). Papich 5e gives only dog and horse doses and Plumb’s 10e (pp.413–415) only dog, cat and horse doses. Plumb’s 10e p.414: do not use dipyrone in any food-producing animal (US position; approved for other species in some countries). Follow the local product label for withdrawal (banned in food animals in some countries). Agranulocytosis risk.
• Calves: Label-sourced (Vetalgin): 5–15 mL slowly IV in calves (≈25–50 mg/kg). Not in Papich 5e or Plumb’s 10e, which says not to use dipyrone in any food-producing animal (p.414, US position). Follow the local label withdrawal.

Horses

• Colic / post-op pain: Label-sourced (500 mg/mL product): 20–60 mL (10–30 g) slowly IV per adult horse (≈25–50 mg/kg for 500 kg). Papich 5e and Plumb’s 10e (p.415) give horses only the antipyretic regimen (30 mg/kg IV — see that row); neither gives a colic/analgesic dose.
• Control of pyrexia: Plumb’s 10e p.415 (label dosage; FDA-approved): 30 mg/kg IV once or twice daily (12-hour intervals) for up to 3 days; under field conditions once-daily treatment controlled pyrexia in most horses. Papich 5e: 30 mg/kg IV every 12 hours for up to 3 days. Use with caution in horses at risk of haemorrhage or on nephrotoxic drugs (Plumb’s 10e p.413).

Goats

• Pain / pyrexia: Label-sourced: 2–8 mL IM (≈25–50 mg/kg). Not in Papich 5e or Plumb’s 10e, which says not to use dipyrone in any food-producing animal (p.414, US position). Follow the local label withdrawal.

Sheep

• Pain / pyrexia: Label-sourced: 2–8 mL IM (≈25–50 mg/kg). Not in Papich 5e or Plumb’s 10e, which says not to use dipyrone in any food-producing animal (p.414, US position). Follow the local label withdrawal.

Pigs

• Pain / pyrexia: Label-sourced: 10–30 mL slowly IV (≈25–50 mg/kg). Not in Papich 5e or Plumb’s 10e, which says not to use dipyrone in any food-producing animal (p.414, US position). Follow the local label withdrawal.

Buffalo

• Colic / post-op / pyrexia: Label-sourced (Vetalgin/Novalgin — buffalo labelled with cattle): 20–40 mL (10–20 g) per adult slowly IV (≈25–50 mg/kg). Not in Papich 5e or Plumb’s 10e, which says not to use dipyrone in any food-producing animal (p.414, US position). Follow the local label withdrawal.

Contraindications

Hypersensitivity to pyrazolones. Pre-existing haematologic disease (history of agranulocytosis / aplastic anaemia). Use with caution in dehydrated patients (renal compromise). Cats: the references disagree — Papich 5e says safe doses are not established in cats; Plumb’s 10e p.415 reports 25 mg/kg IV q24h or 12.5 mg/kg IV q12h for post-operative analgesia, with unclear efficacy (p.414). Plumb’s 10e p.414: do not use in horses intended for human consumption or in any food-producing animal (US position — dipyrone is approved for other species in some countries).

Species-specific warnings

Cats: References disagree: Papich 5e — safe doses not established in cats; Plumb’s 10e p.415 — 25 mg/kg IV q24h or 12.5 mg/kg IV q12h reported for post-operative analgesia, efficacy unclear. Use only with informed caution; watch for vomiting and salivation.

Cattle: Slow IV preferred for analgesia and pyrexia. Withdrawal: milk 2 d, meat 12 d.

Horses: Workhorse for visceral colic analgesia. 20–60 mL slow IV.

Adverse effects

• Rare agranulocytosis / aplastic anaemia (idiosyncratic — primarily a human concern)
• Hypotension on rapid IV bolus — give slowly over 1–2 min
• Allergic reactions in sensitised animals
• Methaemoglobinaemia / haemolytic anaemia in cats (avoid)

Drug interactions

• Chlorpromazine: severe hypothermia reported in combination
• Other NSAIDs: additive GI / renal risk — usually NOT combined
• Anticoagulants: minor — dipyrone has mild antiplatelet effect
• Methotrexate: reduced renal clearance → toxicity risk

Pregnancy and lactation

Avoid in late pregnancy in cattle (risk of weak labour from antispasmodic effect at the cervix). Used by some practitioners specifically to relax a tight cervix at parturition — use with informed judgement.

Monitoring

• Withdrawal periods strictly: milk 2 d, meat 12 d cattle / 3 d pig / 5 d horse
• CBC every 14 days if used on prolonged courses
• Cardiovascular status during slow IV — pause if hypotension develops

Toxicity and overdose

Rapid IV bolus can cause hypotension — always give slowly. Idiosyncratic agranulocytosis is the headline human-medicine concern; clinically rare in animals but reported. Cats: Papich 5e says safe doses are not established; Plumb’s 10e reports post-operative doses, with vomiting and salivation as adverse effects.

Clinical pearls

• Equine colic: 20–60 mL Vetalgin slow IV is the workhorse for visceral analgesia in Indian practice
• Cervical spasm at parturition: 20–30 mL IV in a 300 kg cow relaxes the cervix within 10–15 min
• Pyrexia: faster antipyresis than meloxicam alone — useful when the cow needs to eat
• Cats: only Plumb’s 10e gives a dose (post-operative, efficacy unclear) — Papich 5e says safe doses are not established
• Watch for transient hypotension if bolused fast — give over 1–2 min

Mechanism of action

Pyrazolone-class non-opioid analgesic. Active metabolite (4-methylaminoantipyrine) inhibits central COX-3 and modulates endocannabinoid / opioidergic pathways. Antipyretic effect is rapid (within 15–30 min of IV administration). Mild antispasmodic action makes it useful for visceral / smooth-muscle pain (colic, urethral spasm, cervical spasm) where pure NSAIDs are less effective.

Formulations and products

• Vetalgin VET 500 mg/mL injection (MSD, 33 mL vial)
• Vetalgin VET (MSD Animal Health) — 500 mg/mL (Dipyrone 0.5 g/mL + Chlorbutol 0.4 % preservative), Injection

Storage

Vials 15–25 °C, protected from light. Multidose vial: discard 28 days after broaching.

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 analgesics

• Bupivacaine
• Buprenorphine
• Butorphanol
• Codeine
• Fentanyl
• Gabapentin
• Hydromorphone
• Lidocaine HCl

Frequently asked questions