Butorphanol: veterinary dose and monograph

At a glance

Drug class

Analgesic

Also known as

Torbutrol, Torbugesic, Stadol, Dolorex

Species with doses

Dogs, Cats, Cattle, Horses, Pigs, Birds, Rabbits, Ferrets, Reptiles, Camelids, Hedgehogs, Sugar gliders and Primates

General dose range

0.1–0.5 mg/kg IM q4–6h — check the species tables for the indication

Routes

SC, PO, IV, IM

Last reviewed

1 October 2026

Indications

• Canine antitussive (chronic non-productive cough)
• Pre-anaesthetic and short-procedure analgesia
• Visceral / colic analgesia (esp. equine)
• Reversal of mu-agonist CNS / respiratory depression
• Antiemetic prior to cisplatin (dog)

Butorphanol 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

• Antitussive (label): Papich 5e and Plumb’s p.173 (Torbutrol label): 0.055–0.11 mg/kg SC q6–12h; treatment should not normally be needed beyond 7 days.
• Antitussive (oral): Plumb’s p.173 (label): 0.55 mg/kg PO q6–12h, increasing to 1.1 mg/kg (one 5 mg tablet per 20 lb and 10 lb respectively), for no more than 7 days; 0.05–1 mg/kg q6–12h (Johnson). Papich 5e: 0.5–1 mg/kg q6–12h PO.
• Analgesia (mild–moderate): Plumb’s p.173 (Perkowski 2006): 0.1–0.5 mg/kg IV, IM or SC — mild to moderate (good visceral) analgesia; sedation 2–4 h but analgesia may last 1 h or less. Papich 5e: 0.2–0.4 mg/kg q2–4h IV, IM or SC; CRI 0.2–0.4 mg/kg load then 0.1–0.2 mg/kg/h; epidural 0.25 mg/kg (Valverde).
• Reversal of mu-agonist sedation: Plumb’s p.173 (Quandt 2009): 0.05–0.1 mg/kg IV — partially reverses mu-agonist sedation and respiratory depression while preserving some analgesia (unlike naloxone).
• Analgesia — CRI: Papich 5e: loading 0.2–0.4 mg/kg IV then 0.1–0.2 mg/kg/h. Plumb’s p.173 (Hellyer 2006): 0.1–0.4 mg/kg/h, occasionally used for abdominal pain.

Cats

• Analgesia (mild–moderate): Plumb’s p.173 (Perkowski 2006): 0.1–0.5 mg/kg IV, IM or SC; analgesia may last 1 h or less. Papich 5e: 0.2–0.8 mg/kg q2–6h IV or SC, or 1.5 mg/kg q4–8h PO; sedation 0.2–0.5 mg/kg IV or IM.
• Post-op analgesia — IV loading dose (before CRI): Plumb’s p.173 (Lichtenberger 2006): loading dose 0.1–0.2 mg/kg IV, then 0.1–0.2 mg/kg/h, usually with ketamine (0.1 mg/kg load, 0.4 mg/kg/h). Papich 5e: 0.2–0.4 mg/kg load then 0.1–0.2 mg/kg/h.
• Post-op analgesia — CRI: Papich 5e and Plumb’s p.173 (Lichtenberger 2006): 0.1–0.2 mg/kg/h IV after a loading dose.

Cattle

• Analgesia (extra-label): Plumb’s p.174 (Walz 2006): 0.02–0.25 mg/kg IV or SC (20–30 mg total IV for an adult), duration about 4 h; suggested withdrawal 4 days meat, 72 h milk. Papich 5e: ruminants 0.05–0.2 mg/kg IV; with xylazine 0.01–0.02 mg/kg IV.

Horses

• Analgesia (label): Plumb’s p.174 (Torbugesic label): 0.1 mg/kg IV q3–4h, not to exceed 48 h. Papich 5e: 0.2–0.4 mg/kg q3–4h IV (lower doses 0.02–0.1 mg/kg IV used to limit reduced GI motility); CRI 13–24 µg/kg/h. ARCI Class 3.
• Colic analgesia (with xylazine): Plumb’s p.174: moderate to marked abdominal pain 0.01–0.02 mg/kg IV alone or with xylazine (Moore); 5–10 mg total with xylazine 100–200 mg IV for a 450–500 kg horse; a CRI of 23.7 µg/kg/h causes fewer GI effects (Zimmel). Papich 5e: sedation 0.01–0.06 mg/kg IV.

Pigs

• Miniature/pet pig — analgesia: Carpenter Exotic Animal Formulary 6th ed, Table 12-5 (p.668): miniature pigs 0.1–0.3 mg/kg SC/IM q4–6h (or q8–12h); 0.1–0.4 mg/kg IM/IV. Also widely used in anaesthetic combinations with ketamine/dexmedetomidine.

Buffalo

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

• Analgesia (extra-label): Plumb’s p.174 (Walz 2006): 0.02–0.25 mg/kg IV or SC (20–30 mg total IV for an adult), duration about 4 h; suggested withdrawal 4 days meat, 72 h milk. Papich 5e: ruminants 0.05–0.2 mg/kg IV; with xylazine 0.01–0.02 mg/kg IV.

Birds

• Analgesia (psittacines): Plumb’s p.174: 1–4 mg/kg IM or IV q2–3h as analgesic/sedative/pre-anaesthetic (Lennox); 1–4 mg/kg q4h IM, IV or PO (Bays). Kappa agonists are relatively effective in birds.

Rabbits

• Post-surgical analgesia (rabbits): Plumb’s p.174 (Ivey & Morrisey 2000): rabbits 0.1–0.5 mg/kg IV or SC q2–4h; lower doses may work better (ceiling effect). Post-op 0.4 mg/kg SC q4–6h (Huerkamp 1995); CRI 0.1–0.2 mg/kg load then 0.1–0.2 mg/kg/h (Lichtenberger 2006).

Ferrets

• Analgesia / sedation: Plumb's p.174: butorphanol alone 0.05–0.1 mg/kg IM/SC. Combos: butorphanol 0.2 mg/kg + xylazine 2 mg/kg IM, or butorphanol 0.1 mg/kg + ketamine 5 mg/kg + medetomidine 80 µg/kg IM.

Reptiles

• Analgesia: Plumb's p.175 (Bays 2006): 0.05–1 mg/kg q12h IM/IV/PO/SC; up to 20 mg/kg in tortoises. Kappa-agonist analgesia is more reliable than mu-agonists in many reptile species.

Camelids

• Analgesia; sedation combos: Plumb's p.175 (Miesner 2009): analgesia 0.1 mg/kg IV, IM or SC q4–6h. Recumbent field anaesthesia (Wolff 2009): alpacas butorphanol 0.046 + xylazine 0.46 + ketamine 4.6 mg/kg; llamas 0.037 + 0.37 + 3.7 mg/kg, combined IM.

Hedgehogs

• Analgesia: Carpenter Exotic Animal Formulary 6th ed, Table 8-6 (p.518): hedgehogs 0.05–0.4 mg/kg PO/SC/IM q6–12h (or q6–8h). Less useful than pure mu-agonists for moderate-to-severe pain — dose more frequently.

Sugar gliders

• Analgesia / sedation: Carpenter Exotic Animal Formulary 6th ed, Table 7-3 & 7-4 (p.499–500): sugar gliders 0.1–0.5 mg/kg SC/IM q6–8h (analgesia); 0.4–1 mg/kg SC/IM for sedation for minor procedures. Higher doses may cause sedation.

Primates

• Analgesia (New World primates): Carpenter Exotic Animal Formulary 6th ed, Table 13-4 (p.692): New World primates/marmosets/lemurs 0.02 mg/kg SC/IM/IV q8h; monkeys 0.05 mg/kg IM q8h; prosimians 0.1–0.4 mg/kg SC/IM/IV q3–4h. Behaves more as an agonist in primates — may cause profound respiratory depression; reverse with naloxone.

Contraindications

Hypersensitivity. Use caution in head trauma / raised CSF pressure, hypothyroid, severe renal/adrenal insufficiency, MDR1-mutation breeds (reduce 25–50%), liver disease (per dog label), heartworm disease, lower-respiratory disease with copious mucous, turtles/tortoises (may cause respiratory depression). Schedule IV controlled substance.

Species-specific warnings

Dogs: Useful for mild pain and as antitussive. Inadequate for moderate-to-severe surgical pain — pair with NSAID or pure mu.

Cats: Wider safety margin in cats than pure mu agonists. Useful for short procedures and visceral pain. Can cause mild dysphoria at high doses.

Horses: Standard sedation pairing with xylazine. AVOID alone — excitement / pawing. Foals: lower doses.

Cattle: Used in cattle for surgical analgesia at 0.05 mg/kg IM. Extra-label — withdrawal periods not established. Use ketoprofen / meloxicam for inflammation instead.

Adverse effects

• Sedation, occasional excitement / dysphoria
• Mild respiratory depression
• Ataxia (especially horses)
• Anorexia or rare diarrhoea
• Equine: head-tossing / increased ambulation if rapid IV at high dose; transient nystagmus, salivation, seizures at very high IV dose

Drug interactions

• Pure mu agonists (morphine, methadone, hydromorphone, fentanyl): butorphanol partially ANTAGONISES — reduces analgesia. Avoid concurrent. Use as antagonist for mu overdose only if naloxone unavailable.
• Acepromazine: synergistic sedation — "neuroleptanalgesia" combo (0.05 mg/kg ACP + 0.2 mg/kg butorphanol IM)
• Alpha-2 agonists (xylazine, dexmedetomidine): synergistic sedation and analgesia
• Benzodiazepines (diazepam, midazolam): mild additive sedation
• Inhalant anaesthetics: reduces MAC modestly (~10%)
• CNS depressants (general): additive depression

Pregnancy and lactation

Crosses placenta — neonatal respiratory depression possible if given at delivery. Excreted in milk in low amounts. Generally used cautiously in pregnant patients; reversal with naloxone available for neonate if needed.

Monitoring

• Sedation depth — re-dose at half initial if needed
• Respiratory rate — less of a concern than with pure mu but monitor
• Pain scoring — if inadequate at ceiling dose, transition to pure mu agonist (separate by 4 h)
• Cats: monitor for excitement / dysphoria

Toxicity and overdose

Wide therapeutic margin. Overdose: profound sedation, ataxia, salivation, respiratory depression (less than pure mu agonists due to ceiling effect). Cats may show excitement / dysphoria at higher doses. Horses: occasional excitement / pawing.

Management: Naloxone partially reverses (kappa effects respond poorly) — 0.02–0.04 mg/kg IV/IM titrated to effect. Supportive: airway, oxygen, IV fluids. Recovery usually within 4–6 h.

Clinical pearls

• Mild-to-moderate visceral pain (post-op spay, dental): dogs 0.2–0.4 mg/kg IV/IM; cats 0.2–0.4 mg/kg IV/IM/SC q4–6h
• Antitussive (kennel cough, collapsing trachea): dogs 0.055 mg/kg SC q6–12h or 0.5–1 mg/kg PO q6–12h
• Horse colic premedication: 0.01–0.02 mg/kg IV with xylazine 0.5 mg/kg IV — classic equine sedation combo
• Cat ovariohysterectomy: 0.2 mg/kg IM with dexmedetomidine + ketamine ("Kitty Magic")
• Ceiling effect: doses above 0.4 mg/kg (dog) / 0.8 mg/kg (cat) waste drug without more analgesia
• If butorphanol given first and patient still painful: SWITCH to pure mu (morphine, methadone) — separate by 4 h to clear partial antagonism

Mechanism of action

Synthetic mixed agonist-antagonist opioid. Partial agonist at kappa receptors (analgesia + mild sedation), partial antagonist / weak agonist at mu receptors (caps mu-mediated analgesia, can reverse pure mu agonists). Excellent antitussive (medulla). Ceiling effect on analgesia — increasing dose past 0.4 mg/kg in dogs / 0.8 mg/kg in cats does NOT increase pain relief. Visceral analgesia better than somatic; insufficient for orthopaedic / surgical pain alone.

Formulations and products

• Torbutrol injection 0.5 mg/mL (dogs)
• Torbugesic-SA 2 mg/mL (cats)
• Torbugesic 10 mg/mL (horses)
• Tablet 1 mg
• Tablet 5 mg
• Tablet 10 mg

Storage

Injectable: 15–25 °C, protect from light. Schedule IV controlled substance in US — store in locked cabinet. 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

• Amantadine
• Aspirin
• Bupivacaine
• Buprenorphine
• Codeine
• Dipyrone (Metamizole)
• Fentanyl
• Gabapentin

Frequently asked questions