Gabapentin: veterinary dose and monograph

At a glance

Drug class

Analgesic

Also known as

Neurontin

Species with doses

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

General dose range

3–10 mg/kg PO q8–12h — check the species tables for the indication

Routes

PO

Last reviewed

1 October 2026

Indications

• Neuropathic pain (chronic / cancer / post-surgical)
• Multimodal analgesia (with NSAIDs and/or opioids)
• Adjunctive anticonvulsant (refractory epilepsy)
• Pre-visit anxiolysis in cats
• Chronic osteoarthritis pain (adjunct)

Gabapentin 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

• Neuropathic / chronic pain: Papich 5e: start 5–15 mg/kg q12h PO, increasing gradually up to 40 mg/kg q8–12h if needed. Plumb’s p.562: 5–10 mg/kg PO two to three times daily (VIN consensus); 2.5–10 (up to 15) mg/kg 1–3 times daily (Posner & Papich); 3 mg/kg once daily for cancer pain (Lascelles). Human oral liquids may contain xylitol — avoid.
• Adjunctive anticonvulsant: Papich 5e: 10–20 mg/kg q8h PO (higher end may be needed). Plumb’s p.562: 10–20 mg/kg q6–8h (Munana — least effective of the newer antiepileptics); 10–30 mg/kg q8–12h (Podell); 10 mg/kg q8h (Platt). Do not stop abruptly.

Cats

• Pre-visit anxiolysis: 50–100 mg per cat PO, 90 min before veterinary visit. Marked sedation at 100 mg. Papich 5e p398: 100 mg/cat (20–30 mg/kg) given 90 minutes before the event.
• Chronic / neuropathic pain: Papich 5e: neuropathic pain 5–10 mg/kg q12h PO. Plumb’s p.562: 2.5–5 mg/kg q12h suggested, starting at 5 mg/kg and increasing to 10 mg/kg (Mathews); 5–10 mg/kg 2–3 times daily (VIN); 50 mg per cat 1–3 times daily (Posner & Papich); 3 mg/kg once daily (Lascelles). Reduce in renal insufficiency; sedation is the usual dose limit.
• Adjunctive anticonvulsant: Papich 5e: 5–10 mg/kg q12h PO, increased to 20 mg/kg q8–12h in some cats. Plumb’s p.562: 5–10 mg/kg q8–12h (Podell; Munana); 5 mg/kg three times daily (Pearce); 10–30 mg/kg q8–12h (Mariani).

Horses

• Neuropathic pain / laminitis: Papich 5e: horses 2.5 mg/kg q8–24h PO, increased as needed; doses of 10 mg/kg and higher q8–12h reached concentrations effective in other species. Oral bioavailability in horses is low (~16%).

Pigs

• Miniature/pet pig — neuropathic / chronic pain: Carpenter Exotic Animal Formulary 6th ed, Table 12-5 (p.669): miniature pigs 5–15 mg/kg PO q12h, then increase gradually as high as 40 mg/kg PO q8–12h prn.

Sugar gliders

• Neuropathic pain / self-mutilation: Carpenter Exotic Animal Formulary 6th ed, Table 7-4 (p.500): sugar gliders 3–5 mg/kg PO q8–24h. Anxiolytic; useful in self-mutilation cases. Start low and titrate — may cause sedation at higher doses.

Primates

• Neuropathic / chronic pain (monkeys): Carpenter Exotic Animal Formulary 6th ed, Table 13-4 (p.694): monkeys/chimpanzees 12.8–13.5 mg/kg PO q8h.

Contraindications

Hypersensitivity. LIQUID FORMULATIONS CONTAINING XYLITOL — FATAL IN DOGS. Reduce dose in renal insufficiency. Abrupt discontinuation may precipitate seizures — taper over 1–2 weeks. Not for food-producing animals.

Species-specific warnings

Dogs: XYLITOL-CONTAINING compounded liquids are TOXIC — verify formulation. Otherwise very safe. Dose-reduce in advanced CKD.

Cats: Excellent pre-visit anxiolytic at 50–100 mg PO 2–3 h before transport. Also useful for chronic OA pain at 5–10 mg/kg PO q8–12h.

Horses: Used for chronic laminitis pain at 5–10 mg/kg PO q8h. Limited published efficacy data; extra-label.

Adverse effects

• Sedation, ataxia (dose-dependent, usually self-limiting)
• Dogs: sedation, ataxia, GI upset
• Cats: marked sedation at higher doses
• Weight gain (chronic use)
• Withdrawal seizures if stopped abruptly

Drug interactions

• CNS depressants (opioids, alpha-2, benzodiazepines, anaesthetics): additive sedation — reduce other drug doses 20–30%
• Antacids (aluminium / magnesium): reduce gabapentin absorption — separate by 2 h
• Hydrocodone: increased gabapentin AUC
• NSAIDs: no significant interaction; complementary analgesia
• Renal-excreted drugs: minimal interaction (gabapentin not metabolised hepatically)

Pregnancy and lactation

Crosses placenta. Limited veterinary data. FDA Category C (human). Generally avoided in pregnancy unless clinically essential.

Monitoring

• Pain scoring — efficacy usually evident within 3–7 days for chronic pain
• Sedation depth — cats may show ataxia at higher doses
• Renal function in CKD patients on chronic dosing — accumulation possible
• Xylitol content of liquid formulations — NEVER give xylitol-containing liquid to dogs
• Drug-seeking behaviour (human) — Schedule V in some US states

Toxicity and overdose

Wide therapeutic margin. Overdose: sedation, ataxia, occasional vomiting / hypersalivation. No respiratory depression, no cardiac effects, no organ toxicity reported. CKD patients: cumulative sedation at standard doses — reduce dose in advanced renal failure. Xylitol-containing oral liquid (some human compounded forms) is TOXIC to dogs — verify formulation.

Management: Supportive care only — usually self-limiting. Activated charcoal if recent ingestion + large dose. Cats / small dogs with hypersalivation: anti-emetic if needed. Hydration. Most overdoses resolve within 12–24 h.

Clinical pearls

• Cats pre-visit anxiolytic: 50–100 mg PO 2–3 h before transport — Schedule V controlled (US) but extremely effective and well tolerated
• Chronic OA / neuropathic pain (dogs): 10–20 mg/kg PO q8h — titrate over 1–2 weeks
• Chronic OA pain (cats): 5–10 mg/kg PO q8–12h
• Refractory seizures (dogs): 10–20 mg/kg PO q8h — adjunct to phenobarbital + KBr
• Compounded liquid: BEWARE xylitol-containing human formulations — verify with compounder
• Renal failure: reduce dose 50% — gabapentin is renally excreted unchanged
• NMDA-mediated wind-up pain (paw amputation, chronic back pain): gabapentin + tramadol + NSAID = multimodal
• Effect builds over 1–2 weeks for chronic pain — explain to owners not to expect immediate effect

Mechanism of action

GABA structural analogue (does NOT bind GABA receptors directly). Binds the α2δ-1 subunit of voltage-gated calcium channels in neurons, reducing presynaptic Ca²⁺ influx and decreasing release of excitatory neurotransmitters (glutamate, substance P, noradrenaline). Effects: anti-neuropathic-pain (signature use), anxiolysis, mild sedation, anticonvulsant. Renal excretion (no hepatic metabolism) — dose-reduce in CKD. Half-life 3–4 h dogs, 3 h cats — q8h dosing for chronic pain; pre-procedural use 1–3 h before.

Formulations and products

• Capsule 100 mg
• Capsule 300 mg
• Capsule 400 mg
• Tablet 600 mg
• Tablet 800 mg

Storage

Capsules / tablets: 15–30 °C, dry. Oral solution: refrigerated, discard 30 days after opening. CAUTION: human oral liquid often contains XYLITOL — toxic to dogs. Verify formulation before dispensing to canine patients.

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

• Butorphanol
• Codeine
• Dipyrone (Metamizole)
• Fentanyl
• Hydromorphone
• Lidocaine HCl
• Methadone
• Morphine Sulfate

Frequently asked questions