Dog · Canis lupus familiaris · typical adult weight 2.00–80.00 kg
Phenobarbital is dosed at 16–20 mg/kg IV Loading dose (give in 4 mg/kg increments q20min) in dogs, per Munana KR. Update seizure management in small animal practice. Vet Clin North Am Small Anim Pract. 2013;43(5):1127-1147. PMID: 23890243 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.1036 (2026-08-01). — Plumb's 10th ed (held) printed p.1006, Phenobarbital monograph spanning p.1006-1010; page located 2026-08-05 from the book's own running heads, verified to name the drug in its body text. — figure located 2026-08-05 at Plumb's 10th ed printed p.1010, Phenobarbital monograph; the page cited previously does not carry it. — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207. Phenobarbital is used in dogs for Status epilepticus (loading), Epilepsy (maintenance). Routes documented in dogs: IV, PO. A typical adult dog weighs 2.00–80.00 kg. ExoticRx lists 2 cited dose rules for Phenobarbital in dogs, drawn from published veterinary references. Verify against current literature before clinical use.
US trade names: Luminal, Solfoton
| Route | Dose | Frequency | Duration | Indication | Evidence | Source |
|---|---|---|---|---|---|---|
| IV | 16–20 mg/kg | Loading dose (give in 4 mg/kg increments q20min) | Emergency loading | Status epilepticus (loading) | Strong | Munana KR. Update seizure management in small animal practice. Vet Clin North Am Small Anim Pract. 2013;43(5):1127-1147. PMID: 23890243 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.1036 (2026-08-01). — Plumb's 10th ed (held) printed p.1006, Phenobarbital monograph spanning p.1006-1010; page located 2026-08-05 from the book's own running heads, verified to name the drug in its body text. — figure located 2026-08-05 at Plumb's 10th ed printed p.1010, Phenobarbital monograph; the page cited previously does not carry it. — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207 |
| PO | 2.5–5 mg/kg | q12h | Lifelong | Epilepsy (maintenance) | Weak | Papich MG. Saunders Handbook of Veterinary Drugs, 4th ed. (2016), p.626 (PDF 654), Small Animal Dosage — Dogs — LOCATOR CONVENTION 2026-08-07: 'p.626' is the PRINTED page number, confirmed by finding the drug named on it in the held copy. — SOURCE EDITION: Saunders Handbook of Veterinary Drugs — ISBN 9780323244855, https://openlibrary.org/isbn/9780323244855 |
Every held source for this drug and species, as printed. Where they differ, both are shown — the choice is yours, not ours.
The sources disagree for this combination. The ranges below do not overlap on a comparable route. This is not an error in one of them — published veterinary references differ, and reconciling them for a particular patient is a clinical judgement.
| Dose (mg/kg) | Route | Source | As printed |
|---|---|---|---|
| 1–2.5 | PO | BSAVA Small Animal Formulary, 10th ed — Part A (Canine and Feline)p.332 | 1-2.5 mg/kg p.o. q12h (authorized dose). However, in one study only 40% of dogs started on |
| 2.5–3 | PO | BSAVA Small Animal Formulary, 10th ed — Part A (Canine and Feline)p.332 | Therefore, initial dose recommendation is usually 2.5-3 mg/kg p.o. q12h. Incremental modifications of the initial dose, based on serum concen |
| 18–24 | IV | BSAVA Small Animal Formulary, 10th ed — Part A (Canine and Feline)p.332 | maintenance phenobarbital: aim for a total loading dose of 18-24 mg/kg, followed by a maintenance dose of 2-3 mg/kg q12h. The loading dose is given as |
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Enhances GABA-A receptor activity by prolonging chloride channel opening. Also blocks AMPA/glutamate receptors. Raises seizure threshold.
First-line anticonvulsant for dogs. Hepatotoxicity with chronic use (monitor liver enzymes and serum levels). PU/PD, polyphagia, sedation (often transient). Hepatic enzyme inducer (many drug interactions). DEA controlled.
Species-specific contraindications and adverse-reaction reports for dogs may differ from canine / feline reference data — consult the primary citations listed with each rule.
Phenobarbital dose ranges in dogs, with cited source references: IV 16–20 mg/kg Loading dose (give in 4 mg/kg increments q20min); PO 2.5–5 mg/kg q12h. Reference ranges from cited sources — verify against current literature before clinical use.
Documented routes for Phenobarbital in dogs: IV, PO.
Cited course lengths for Phenobarbital in dogs include: Emergency loading; Lifelong. Duration depends on the indication — match it to the specific dose rule in the table above.
Phenobarbital is indicated in dogs for: Status epilepticus (loading), Epilepsy (maintenance).
These are general warnings for Phenobarbital across species; consult the dog dosing table above for species-specific guidance. First-line anticonvulsant for dogs. Hepatotoxicity with chronic use (monitor liver enzymes and serum levels). PU/PD, polyphagia, sedation (often transient). Hepatic enzyme inducer (many drug interactions). DEA controlled.
Why a species-specific page? Phenobarbital pharmacokinetics differ across species: dose ranges, intervals, and route preferences are not interchangeable. Cross-extrapolation from canine doses is unsafe in dogs — the rules above are the citations specific to this species, not generic recommendations.
Sourced from published veterinary references; awaiting credentialed clinical reviewer. See our editorial process. Reference only — not veterinary advice.
| 2–3 | IV | BSAVA Small Animal Formulary, 10th ed — Part A (Canine and Feline)p.332 | of 18-24 mg/kg, followed by a maintenance dose of 2-3 mg/kg q12h. The loading dose is given as an initial 12 mg/kg slow i.v. and then after 20 |
| 12 | IV | BSAVA Small Animal Formulary, 10th ed — Part A (Canine and Feline)p.332 | of 2-3 mg/kg q12h. The loading dose is given as an initial 12 mg/kg slow i.v. and then after 20 minutes, two further doses of 4-6 mg/kg slow i.v. 2 |
| 4–6 | IV | BSAVA Small Animal Formulary, 10th ed — Part A (Canine and Feline)p.332 | . and then after 20 minutes, two further doses of 4-6 mg/kg slow i.v. 20 minutes apart. Always wait 20 minutes before giving additional doses as |
| 2–3 | PO | BSAVA Small Animal Formulary, 10th ed — Part A (Canine and Feline)p.332 | 2-3 mg/kg p.o. q12h with propranolol also at 2-3 mg/kg p.o. q12h. BSAVA Small Animal Formulary 10th edition: Part A - Canine and Feline |
| 2–8 | PO | Papich Saunders Handbook of Veterinary Drugs, 4th edp.654 | • 2-8 mg/kg q12h PO. |
| 10–20 | IV | Papich Saunders Handbook of Veterinary Drugs, 4th edp.654 | • Status epilepticus: Administer in increments of 10-20 mg/kg IV to effect. |
Figures are transcribed from the cited page or table of each held edition and are shown for reference only. They are not dose recommendations, they do not feed the calculator, and none has been reviewed by a veterinarian.