# Levetiracetam: veterinary dose and monograph

> Levetiracetam is a veterinary drug. Pyrrolidone anticonvulsant — fundamentally different mechanism from phenobarbital / KBr / benzodiazepines (no GABA, no Na/Ca channel block). Indications include idiopathic epilepsy (first-line or add-on); refractory epilepsy (add-on to phenobarbital / KBr); status epilepticus (IV bolus alternative to phenobarbital). This monograph lists 9 reference doses for dogs, cats and horses, each with route, frequency and source.

Source: https://vetmasterji.com/drugs/levetiracetam · Last reviewed: 2026-10-01

## At a glance

- **Drug class:** Veterinary drug
- **Also known as:** Keppra, Keppra XR
- **Species with doses:** Dogs, Cats and Horses
- **General dose range:** 20–60 mg/kg PO q8h — check the species tables for the indication
- **Routes:** PO, IV, Rectal
- **Last reviewed:** 1 October 2026

## Indications

- Idiopathic epilepsy (first-line or add-on)
- Refractory epilepsy (add-on to phenobarbital / KBr)
- Status epilepticus (IV bolus alternative to phenobarbital)
- Pulse therapy for cluster seizures ("LevoLoad" 60 mg/kg single dose at cluster onset)
- Hepatic disease patients where phenobarbital is contraindicated
- Geriatric epilepsy (better-tolerated than phenobarbital in older patients)

## Levetiracetam 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

*Levetiracetam doses for dogs*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Maintenance AED (monotherapy or adjunct) | 20 mg/kg | PO | q8h | — |
| Status epilepticus / cluster seizures (IV) | 20–60 mg/kg | IV | bolus; repeat to max 60 mg/kg | — |
| Maintenance — extended-release tablets | 30 mg/kg | PO | q12h | — |
| Cluster seizures — rectal (no IV access) | 40 mg/kg | Rectal | single dose | — |

- Maintenance AED (monotherapy or adjunct): Papich 5e and Plumb’s p.723: 20 mg/kg PO q8h. Plumb’s (Dewey 2005): increase in 20 mg/kg increments until efficacy, adverse effects or cost limit. Dogs on phenobarbital clear levetiracetam faster and may need higher or more frequent doses.
- Status epilepticus / cluster seizures (IV): Papich 5e: 20 mg/kg IV bolus, repeated if necessary up to 60 mg/kg. Plumb’s p.723: 60 mg/kg IV bolus was well tolerated in normal dogs (Dewey 2008); status epilepticus — lorazepam 0.2 mg/kg IV then levetiracetam 60 mg/kg IV (Podell 2009). Continue oral maintenance afterwards.
- Maintenance — extended-release tablets: Papich 5e: XR tablets 30 mg/kg PO q12h. Do not split or crush XR tablets.
- Cluster seizures — rectal (no IV access): Papich 5e: 40 mg/kg per rectum using the 100 mg/mL solution produced effective concentrations; in many dogs the volume is too large to be practical.

### Cats

*Levetiracetam doses for cats*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Maintenance AED | 20 mg/kg | PO | q8h | — |
| Maintenance — extended-release tablet | 500 mg/cat | PO | q24h | — |

- Maintenance AED: Papich 5e: 20 mg/kg PO q8h. Plumb’s p.723 (Pearce 2006; Bailey & Dewey 2009): start 20 mg/kg PO three times daily as an add-on to phenobarbital; increase in 20 mg/kg increments if ineffective. Bitter — compounded flavoured liquid helps.
- Maintenance — extended-release tablet: Papich 5e: 500 mg XR tablet per cat once daily (≈94 mg/kg). Do not split tablets.

### Horses

*Levetiracetam doses for horses*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Seizures — short-term IV | 30 mg/kg | IV | single dose | — |
| Seizures — oral maintenance (Papich 5e, q24h) | 30 mg/kg | PO | q24h | — |
| Seizures — oral maintenance (Plumb’s 10e, q12h) | 30 mg/kg | PO | q12h | — |

- Seizures — short-term IV: Papich 5e: horses 30 mg/kg IV for short-term treatment. Plumb’s 10e gives no IV horse dose, and neither reference gives a foal-specific dose.
- Seizures — oral maintenance (Papich 5e, q24h): Papich 5e: horses 30 mg/kg q24h PO. REFERENCE CONFLICT on interval: Plumb’s 10e p.748 gives the same 30 mg/kg but every 12 hours (next row).
- Seizures — oral maintenance (Plumb’s 10e, q12h): Plumb’s 10e p.748 (extra-label): anticonvulsant, based on pharmacokinetic studies and presumed therapeutic levels — 30 mg/kg PO every 12 hours using immediate-release tablets. Crushed extended-release tablets gave similar serum concentrations but may be cost-prohibitive.

## Contraindications

Hypersensitivity. Severe renal impairment: reduce dose (renally excreted unchanged — 66% of dose). Caution in pregnancy due to limited data. No food-animal use approved.

## Species-specific warnings

> **Caution:** Dogs: First-line option for hepatic disease, geriatric, and owner-preference cases. q8h dosing essential (short half-life ~3 h). XR for q12h convenience.

> **Caution:** Cats: First-line AED for cats — phenobarbital is acceptable but more hepatotoxic; KBr is contraindicated in cats. Bitter — compound.

> **Caution:** Horses: Foal seizures: 30 mg/kg IV load then 10–20 mg/kg q8h. Adult horse use is extra-label and rare.

## Adverse effects

- Sedation, ataxia (mild, transient — usually resolves in 1–2 weeks)
- Hyporexia, vomiting (uncommon)
- Behavioural changes (rare — agitation, aggression)
- Thrombocytopenia (rare)
- NO hepatotoxicity (major advantage over phenobarbital)
- NO PU/PD/polyphagia (advantage over phenobarbital / KBr)

## Drug interactions

- Phenobarbital, KBr: synergistic — common combination in refractory epilepsy
- No clinically significant CYP interactions (no hepatic metabolism)
- No interactions with: opioids, NSAIDs, anaesthetics, antibiotics
- CNS depressants: additive sedation only

## Pregnancy and lactation

Limited vet data. FDA Category C (human). Crosses placenta. In epileptic dams, continue therapy as seizures pose greater risk than the drug.

## Monitoring

- Seizure log — frequency, duration, post-ictal
- No mandatory serum drug monitoring (unlike phenobarbital) — clinical response is the endpoint
- Optional serum trough (4–37 µg/mL target) for refractory cases
- Renal function in advanced CKD — dose reduction if BUN/Cr elevated
- CBC every 6 months — rare thrombocytopenia
- No hepatic monitoring needed (no hepatic metabolism)

## Toxicity and overdose

Extremely wide therapeutic margin. Overdose: sedation, ataxia, occasional vomiting — usually self-limiting. No hepatotoxicity, no cardiotoxicity, no nephrotoxicity at therapeutic doses. Reduce dose in advanced CKD (renally excreted).

Management: Supportive only — overdose well tolerated. Activated charcoal if recent ingestion. IV fluids. Monitor for sedation. Hemodialysis effective in severe overdose.

## Clinical pearls

- First-line for: hepatic disease patients, geriatric patients, owners refusing phenobarbital, cats (no KBr available)
- Adjunct to phenobarbital in refractory epilepsy — start at 20 mg/kg PO q8h, titrate to 30–40 mg/kg q8h
- Status epilepticus IV: 30–60 mg/kg IV over 5 min — safer than phenobarbital IV (no respiratory depression)
- Pulse therapy "LevoLoad": 60 mg/kg single dose at first sign of cluster seizures
- XR formulation (Keppra XR) allows q12h dosing in dogs >20 kg — improves compliance
- NO need for serum monitoring routinely — major workflow advantage
- NO hepatic interactions — safe with cyclosporine, phenobarbital, opioids, NSAIDs simultaneously
- Bitter taste in cats — compound to flavoured liquid or use crushed in food

## Mechanism of action

Pyrrolidone anticonvulsant. Binds the synaptic vesicle protein SV2A — modulates neurotransmitter release at hyperactive synapses but spares normal synaptic function. Does NOT affect GABA, Na/Ca channels, or NMDA receptors — fundamentally different from all other AEDs. Renally excreted unchanged (no hepatic metabolism) — no drug-drug interactions, no enzyme induction.

## Formulations and products

- Keppra 250 / 500 / 750 / 1000 mg tablet
- Keppra oral solution 100 mg/mL
- Keppra XR 500 / 750 mg extended-release tablet
- Keppra IV 100 mg/mL

## Storage

Tablets: 15–30 °C, dry. Oral solution: refrigerated after opening, discard 3 months. IV: 15–30 °C, do not freeze.

## Before you use this dose

> **Caution:** 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.

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## Frequently asked questions

### What is the dose of Levetiracetam for dogs?

Reference doses for Levetiracetam in dogs: 20 mg/kg PO q8h (Maintenance AED (monotherapy or adjunct)); 20–60 mg/kg IV bolus; repeat to max 60 mg/kg (Status epilepticus / cluster seizures (IV)); 30 mg/kg PO q12h (Maintenance — extended-release tablets); 40 mg/kg Rectal single dose (Cluster seizures — rectal (no IV access)). Confirm against the label and the patient before use.

### What is the dose of Levetiracetam for cats?

Reference doses for Levetiracetam in cats: 20 mg/kg PO q8h (Maintenance AED); 500 mg/cat PO q24h (Maintenance — extended-release tablet). Confirm against the label and the patient before use.

### What is the dose of Levetiracetam for horses?

Reference doses for Levetiracetam in horses: 30 mg/kg IV single dose (Seizures — short-term IV); 30 mg/kg PO q24h (Seizures — oral maintenance (Papich 5e, q24h)); 30 mg/kg PO q12h (Seizures — oral maintenance (Plumb’s 10e, q12h)). Confirm against the label and the patient before use.

### When should Levetiracetam not be used?

Hypersensitivity. Severe renal impairment: reduce dose (renally excreted unchanged — 66% of dose). Caution in pregnancy due to limited data. No food-animal use approved.

### What are the side effects of Levetiracetam in animals?

Sedation, ataxia (mild, transient — usually resolves in 1–2 weeks); Hyporexia, vomiting (uncommon); Behavioural changes (rare — agitation, aggression); Thrombocytopenia (rare); NO hepatotoxicity (major advantage over phenobarbital); NO PU/PD/polyphagia (advantage over phenobarbital / KBr).

## Sources

- Plumb's Veterinary Drug Handbook
- ACVIM Small Animal Consensus Statement on Epilepsy 2016
- Papich, Papich Handbook of Veterinary Drugs, 5th edition

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VetMasterJi is a clinical decision-support and education platform for veterinary professionals and students. It does not provide veterinary advice, diagnosis or treatment for specific animals. All drug doses, calculators and differentials are references that must be independently verified before clinical use; the attending registered veterinarian remains solely responsible for every clinical decision.