Dog · Canis lupus familiaris · typical adult weight 2.00–80.00 kg
Phenytoin is dosed at 10 mg/kg IV single slow i.v. dose over 5 min in dogs, per BSAVA Small Animal Formulary 10th Ed, printed p.322 (corpus p.338) '10 mg/kg i.v. slowly'; interval corroborated by Papich Saunders Handbook 4th Ed printed p.634 (corpus p.663) 'Antiarrhythmic: ... 10 mg/kg IV over 5 min' — SOURCE EDITION: BSAVA Small Animal Formulary, Part A — Canine and Feline — ISBN 9781910443705, https://openlibrary.org/isbn/9781910443705; Saunders Handbook of Veterinary Drugs — ISBN 9780323244855, https://openlibrary.org/isbn/9780323244855. Phenytoin is used in dogs for Status epilepticus (alternative to diazepam). Routes documented in dogs: IV. A typical adult dog weighs 2.00–80.00 kg. ExoticRx lists 1 cited dose rule for Phenytoin in dogs, drawn from published veterinary references. Verify against current literature before clinical use.
US trade names: Dilantin
| Route | Dose | Frequency | Duration | Indication | Evidence | Source |
|---|---|---|---|---|---|---|
| IV | 10 mg/kg | single slow i.v. dose over 5 min | Single dose for acute seizures | Status epilepticus (alternative to diazepam) | Weak | BSAVA Small Animal Formulary 10th Ed, printed p.322 (corpus p.338) '10 mg/kg i.v. slowly'; interval corroborated by Papich Saunders Handbook 4th Ed printed p.634 (corpus p.663) 'Antiarrhythmic: ... 10 mg/kg IV over 5 min' — SOURCE EDITION: BSAVA Small Animal Formulary, Part A — Canine and Feline — ISBN 9781910443705, https://openlibrary.org/isbn/9781910443705; 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 |
|---|---|---|---|
| 10 | IV | BSAVA Small Animal Formulary, 10th ed — Part A (Canine and Feline)p.338 | 10 mg/kg i.v. slowly; 30-50 mg/kg p.o. q8h. |
| 30–50 | PO | BSAVA Small Animal Formulary, 10th ed — Part A (Canine and Feline)p.338 | 10 mg/kg i.v. slowly; 30-50 mg/kg p.o. q8h. |
| 15 | IV | BSAVA Small Animal Formulary, 10th ed — Part A (Canine and Feline)p.338 | following a benzodiazepine, fosphenytoin at 15 mg/kg phenytoin equivalent (22.5 mg/kg) i.v. slowly (1 ml/min). |
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Stabilizes neuronal membranes by blocking voltage-dependent sodium channels in their inactive state, preventing repetitive firing. Does not affect normal neuronal activity.
Hepatotoxicity in dogs with chronic use. Rapid hepatic metabolism in dogs limits usefulness. Zero-order kinetics make dosing unpredictable. Gingival hyperplasia. Generally not recommended in dogs — phenobarbital preferred.
Species-specific contraindications and adverse-reaction reports for dogs may differ from canine / feline reference data — consult the primary citations listed with each rule.
Phenytoin dose range in dogs, with cited source references: IV 10 mg/kg single slow i.v. dose over 5 min. Reference ranges from cited sources — verify against current literature before clinical use.
Documented routes for Phenytoin in dogs: IV.
Cited course lengths for Phenytoin in dogs include: Single dose for acute seizures. Duration depends on the indication — match it to the specific dose rule in the table above.
Phenytoin is indicated in dogs for: Status epilepticus (alternative to diazepam).
These are general warnings for Phenytoin across species; consult the dog dosing table above for species-specific guidance. Hepatotoxicity in dogs with chronic use. Rapid hepatic metabolism in dogs limits usefulness. Zero-order kinetics make dosing unpredictable. Gingival hyperplasia. Generally not recommended in dogs — phenobarbital preferred.
Why a species-specific page? Phenytoin 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.
| 22.5 |
| IV |
| BSAVA Small Animal Formulary, 10th ed — Part A (Canine and Feline)p.338 |
| zodiazepine, fosphenytoin at 15 mg/kg phenytoin equivalent (22.5 mg/kg) i.v. slowly (1 ml/min). |
| 50–100 | PO | BSAVA Small Animal Formulary, 10th ed — Part A (Canine and Feline)p.338 | 50-100 mg/kg p.o. q24h sustained release phenytoin. |
| 20–35 | — | Papich Saunders Handbook of Veterinary Drugs, 4th edp.663 | • Anticonvulsant: 20-35 mg/kg q8h. |
| 30 | PO | Papich Saunders Handbook of Veterinary Drugs, 4th edp.663 | • Antiarrhythmic: 30 mg/kg q8h PO or 10 mg/kg IV over 5 min. |
| 10 | PO | Papich Saunders Handbook of Veterinary Drugs, 4th edp.663 | • Antiarrhythmic: 30 mg/kg q8h PO or 10 mg/kg IV over 5 min. |
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.