ExoticRx · exoticrx.com/drugs/phenytoin
US brand names:Dilantin
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'. Verify against current literature before clinical use.
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 references:All Dog (Domestic) drugs
Each ExoticRx dose rule is graded by the strength of its primary evidence — see the editorial process.
A dog/cat sample is shown here. Cited dosing for all 1 species — reptiles, birds, pocket pets, livestock, and equine — is free on the per-species pages above. Pro adds the weight-based calculator for every species.
| Species | Route | Dose | Frequency | Evidence | Source |
|---|---|---|---|---|---|
| Dog (Domestic) | IV | 10 mg/kg | single slow i.v. dose over 5 min | Moderate | 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' |
| Dog (Domestic) | PO | 15–40 mg/kg | q8h | Moderate | Plumb's Veterinary Drug Handbook, 9th Ed |
Upgrade to Pro or Student to unlock the full dose ranges and frequency for every species. The drug's mechanism, warnings, indications, and cited sources are free to read.
View PlansSource citations and evidence levels available on the live page. Reference only — verify against current literature before clinical use.