Tramadol: veterinary dose and monograph

At a glance

Drug class

Analgesic

Also known as

Ultram

Species with doses

Dogs, Cats, Horses, Pigs, Hedgehogs and Sugar gliders

General dose range

2–5 mg/kg PO q6–8h — check the species tables for the indication

Routes

PO, IV

Last reviewed

1 October 2026

Indications

• Post-operative pain (multimodal)
• Chronic / cancer / degenerative joint disease pain
• Antitussive (occasional)
• Equine chronic laminitis pain (with ketamine, in studies)

Tramadol 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

• Acute / chronic pain: Papich 5e: 5 mg/kg q6–8h PO. Plumb’s p.1138 (KuKanich 2010): 5 mg/kg PO q6–8h, up to 10 mg/kg q6–8h in non-responsive dogs (efficacy not evaluated); full effect in chronic pain may take up to 14 days. Oral bioavailability and active-metabolite production in dogs are low — use within multimodal protocols.
• Peri-operative pain (slow IV): Papich 5e: if an injectable form is available, 4 mg/kg IV q6–8h. Give slowly; watch for transient sedation. Plumb’s gives oral doses only for dogs.
• Mild chronic pain: Plumb’s p.1138: 2–5 mg/kg PO two to three times daily for mild chronic pain, adjusting dose and interval for more severe pain (Grubb); 2–5 mg/kg four times daily as a starting dose (Hellyer). Best combined with an NSAID.

Cats

• Pain (cautious dose): Plumb’s p.1138: 2 mg/kg PO twice daily is a reasonable starting dose (Boothe 2010); 1–2 mg/kg PO q12h (KuKanich 2010). Papich 5e: start at 2 mg/kg and increase up to 4 mg/kg q8–12h PO. Very bitter; watch for dysphoria and mydriasis.
• Chronic mild pain: Plumb’s p.1138 (Grubb 2010): 1–4 mg/kg PO two to three times daily for mild chronic pain, adjusted for severity. Papich 5e: 2 mg/kg increasing to 4 mg/kg q8–12h PO. Full effect in chronic pain may take up to 14 days.

Horses

• Chronic laminitis pain (study, with ketamine CRI): Plumb’s p.1138 (Guedes et al. 2009): chronic laminitis pain 5 mg/kg PO twice daily for 7 days, alone or with ketamine 0.6 mg/kg/h IV for 6 h daily on the first 3 days. Papich 5e: horses 2 mg/kg slow IV or 4–5 mg/kg PO (q6h, extend to q12h if responding); do not exceed 2 mg/kg IV or 5 mg/kg PO.

Pigs

• Miniature/pet pig — pain (multimodal adjunct): Carpenter Exotic Animal Formulary 6th ed, Table 12-5 (p.670): miniature pigs 1–4 mg/kg PO q8h, or 2–4 mg/kg PO q6–24h, or 5 mg/kg IM.

Hedgehogs

• Pain (multimodal adjunct): Carpenter Exotic Animal Formulary 6th ed, Table 8-6 (p.518): hedgehogs 2–4 mg/kg PO q12h.

Sugar gliders

• Pain (multimodal adjunct): Carpenter Exotic Animal Formulary 6th ed, Table 7-4 (p.500): sugar gliders 5–10 mg/kg PO or IM q12h.

Contraindications

Hypersensitivity to tramadol or other opioids. Acetaminophen-combination products contraindicated in cats. Caution with concurrent CNS depressants, seizure-threshold-lowering drugs, pre-existing seizure disorders. Geriatric / debilitated animals. Renal or hepatic impairment (dose adjustment). Withdraw gradually after chronic use. Do NOT crush extended-release tablets.

Species-specific warnings

Dogs: INCONSISTENT analgesia in dogs — recent OA studies show monotherapy minimally effective. Use as multimodal adjunct (with NSAID + gabapentin). Avoid in seizure-prone patients.

Cats: TRUE opioid analgesia in cats (efficient M1 conversion). Doses 1–4 mg/kg PO q8–12h. Bitter — compound to flavoured base.

Horses: Limited use — oral bioavailability poor. IV tramadol 1.5–2 mg/kg evaluated for foal analgesia. Not first-line.

Adverse effects

• CNS: sedation, agitation, anxiety, tremor, dizziness
• GI: inappetence, vomiting, constipation or diarrhoea
• Cats: dysphoria, mydriasis, dose avoidance (unpalatable)
• Pruritus (~10% of human patients)
• Injectable form: respiratory and cardiac depression

Drug interactions

• SSRIs / TCAs / SNRIs (fluoxetine, amitriptyline, clomipramine): SEROTONIN SYNDROME risk — additive serotonergic activity
• Monoamine oxidase inhibitors (selegiline, L-deprenyl): CONTRAINDICATED — fatal serotonin syndrome
• Other opioids: additive analgesia + sedation; risk of stacking
• CNS depressants (acepromazine, benzodiazepines, anaesthetics): additive sedation
• Carbamazepine, phenytoin, rifampicin: induce CYP — reduce tramadol levels
• Cimetidine, fluoxetine: inhibit CYP2D6 — increase M1 metabolite (more analgesia)
• NSAIDs: complementary analgesia (multimodal); no direct interaction

Pregnancy and lactation

Crosses placenta — neonatal opioid withdrawal possible if used late pregnancy. Excreted in milk. Generally avoided in late pregnancy if alternatives available. FDA Category C.

Monitoring

• Pain scoring — efficacy in dogs is inconsistent; switch to gabapentin / NSAID / opioid if inadequate
• Sedation depth — cats especially
• GI: constipation — provide hydration, consider lactulose if chronic
• Concurrent SSRI / TCA medications — major serotonin syndrome risk
• Seizure-prone patients — additional caution

Toxicity and overdose

Cats: more potent opioid effect than in dogs — sedation, dysphoria more common; lower doses (1–4 mg/kg PO q8–12h) needed. Dogs: serotonin syndrome with SSRI co-administration (tremors, hyperthermia, agitation, seizures). Lowers seizure threshold — caution in epileptics. Constipation common. Recent vet evidence shows tramadol monotherapy in dogs is often inadequate for OA pain.

Management: Naloxone PARTIALLY reverses opioid effects (M1) but not serotonergic effects — 0.02–0.04 mg/kg IV. Serotonin syndrome: cyproheptadine 1.1 mg/kg PO q6h, active cooling, IV fluids, diazepam for tremors / seizures. Activated charcoal if recent ingestion.

Clinical pearls

• Dogs: 5 mg/kg PO q8–12h — but recent placebo-controlled OA studies show MINIMAL benefit. Gabapentin or NSAID preferred
• Cats: 1–4 mg/kg PO q8–12h — TRUE analgesia in cats (efficient M1 conversion). Bitter taste — compound into flavoured base
• Multimodal: tramadol + NSAID + gabapentin gives better OA control than tramadol alone
• NEVER with SSRI / TCA / MAO inhibitor — fatal serotonin syndrome reported
• Post-op adjunct: tramadol + carprofen × 5–7 days, then taper to NSAID alone
• Avoid in seizure-prone dogs — lowers threshold
• Compound to a small flavoured tablet/liquid for cats — extremely bitter

Mechanism of action

Atypical centrally acting analgesic. Weak mu-opioid agonist (~6000× weaker than morphine, but active M1 metabolite is ~10× more potent) + serotonin/noradrenaline reuptake inhibition (descending pain inhibition). Dogs convert tramadol to M1 (O-desmethyltramadol) inefficiently — making it a primarily monoaminergic analgesic in dogs rather than an opioid; this is why recent dog OA studies show modest-to-no analgesia. Cats convert tramadol to M1 efficiently — true opioid analgesia in cats.

Formulations and products

• Tablet 50 mg
• Tablet 100 mg
• Injection 50 mg/mL (parenteral)

Storage

Tablets / capsules: 15–30 °C, dry. Schedule IV controlled substance (US) — locked storage. Tablets stable for years.

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

• Nalbuphine
• Paracetamol (Acetaminophen)
• Pethidine (Meperidine)
• Pregabalin

Frequently asked questions