Diazepam: veterinary dose and monograph

At a glance

Drug class

Sedative / anaesthetic

Also known as

Valium, Diastat

Species with doses

Dogs, Cats, Cattle, Horses, Goats, Sheep, Pigs, Rabbits, Ferrets, Guinea pigs, Hamsters, Rats, Mice, Gerbils, Sugar gliders and Primates

General dose range

0.2–1 mg/kg IV prn — check the species tables for the indication

Routes

IV, Rectal, PO, IM

Last reviewed

1 October 2026

Indications

• Status epilepticus / cluster seizures (dogs and cats — emergency IV/PR/IN)
• Pre-anaesthetic sedation / muscle relaxation (often combined with ketamine)
• Functional urethral sphincter hypertonus (dogs and cats)
• Situational anxiety (storms, travel) — short course
• Appetite stimulation in cats (single dose; chronic use contraindicated)
• Adjunctive treatment of metronidazole CNS toxicity

Diazepam 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

• Status epilepticus — IV: Papich 5e: 0.5 mg/kg IV, 0.5–1 mg/kg intranasal or 1 mg/kg rectal, repeat if necessary. Plumb’s p.381: 0.5–1 mg/kg IV (1–2 mg/kg in dogs on phenobarbital), may repeat twice; anticonvulsant effect lasts only 15–30 min, so start a longer-acting drug (phenobarbital) (Knipe; Mariani). Give IV over 1–3 min.
• Cluster seizures — at-home rectal: PER RECTUM using the parenteral solution (or rectal gel). Plumb’s p.381: 0.5–1 mg/kg rectally at seizure onset; dogs on phenobarbital 1–2 mg/kg (Podell; Munana 2010); up to 3 doses in 24 h, ≥10 min apart; owner stays with the dog for 1 h. Papich 5e: 1 mg/kg rectal or 0.5–1 mg/kg intranasal. Dispense in the original glass vial (adsorbs to plastic, light-sensitive).
• Functional urethral sphincter hypertonus: Plumb’s p.382 (Bartges 2003): 0.2 mg/kg PO q8h, or 2–10 mg TOTAL per dog PO q8h (Polzin & Osborne; Lane 2000); 0.5 mg/kg IV (Chew 1986).
• Situational anxiety (short course): Plumb’s p.381: 0.55–2.2 mg/kg PO q8–12h (Haug); 0.5–2.2 mg/kg as needed for storms (Sherman & Mills); 0.5–2 mg/kg PO as needed (Neilson). Papich 5e: 0.5–2 mg/kg q4–6h PO. Avoid in aggressive dogs (disinhibition); tolerance develops.
• CRI for refractory status: Plumb’s p.381 (Platt & McDonnell): 0.1–0.5 mg/kg/h diluted in D5W at the maintenance fluid rate. Papich 5e (dogs and cats): 15 µg/kg/min (1 mg/kg/h), reduced by 50% if side effects occur. Diazepam adsorbs to PVC and can precipitate — use non-PVC lines, protect from light.

Cats

• Status epilepticus — single emergency dose: Papich 5e: 0.5 mg/kg IV (or 0.5–1 mg/kg intranasal, 1 mg/kg rectal). Plumb’s p.381 (Shell 2000): 0.5–1 mg/kg IV to halt a seizure; consider glucose if the cat has received insulin; do not use after chlorpyrifos exposure (potentiates organophosphate toxicity).
• CHRONIC ORAL — CONTRAINDICATED: Chronic oral diazepam in cats has caused FATAL idiosyncratic hepatic necrosis (Center 1996). Phenobarbital is the preferred maintenance anticonvulsant in cats. If absolutely required short-term (<5 days), check baseline + day-3 ALT/AST/bilirubin; STOP at first sign of inappetence/lethargy. Plumb’s p.381 (Mariani 2010): oral maintenance 0.2–1 mg/kg q12h has been used but is associated with fatal hepatic necrosis — phenobarbital is preferred.
• Urine spraying (short course only): Plumb’s p.381: urine marking/anxiety 0.2–0.4 mg/kg PO q12–24h, starting at 0.2 mg/kg q12h (Overall); 1–2.5 mg per cat q8–12h (Reisner); fast-acting anxiolytic 0.2–0.5 mg/kg PO as needed (Neilson). Papich 5e: 1–4 mg per cat q12–24h. Idiosyncratic fatal hepatic necrosis — baseline and follow-up liver enzymes; keep courses short.

Cattle

• Sedation: Papich 5e: cattle, sheep and goats 0.02–0.08 mg/kg IV, up to 0.5 mg/kg slowly IV, to effect — cows may become recumbent at 0.5 mg/kg; do NOT give IM. Plumb’s p.382: sedative in calves 0.4 mg/kg IV (Booth 1988).
• CNS hyperactivity / seizures: Plumb’s p.382 (Bailey 1986): 0.5–1.5 mg/kg IM or IV for CNS hyperactivity and seizures. Papich 5e advises against IM use in ruminants — give slowly IV. Extra-label in food animals.

Horses

• Field anaesthesia — added to ketamine (poor sedation): Plumb’s p.382 (Mathews 1999): when xylazine sedation is marginal, diazepam 0.03 mg/kg IV mixed with the ketamine improves induction and relaxation and prolongs anaesthesia by 5–10 min. Higher doses cause ataxia/recumbency in a standing horse.
• Foal seizure control: Plumb’s p.382 (Sweeney & Hansen 1987): foals 0.05–0.4 mg/kg IV, repeat in 30 min if needed. Papich 5e: seizures 0.1–0.4 mg/kg IV; foal CRI 1–3 mg/h. Give slowly; watch for fasciculations and recumbency. ARCI Class 2.
• Seizures — adult: Papich 5e: seizures 0.1–0.4 mg/kg IV (start with 50–100 mg per horse). Plumb’s p.382 (Sweeney & Hansen 1987): adults 25–50 mg TOTAL IV, repeat in 30 min if necessary.

Goats

• Sedation: Papich 5e: cattle, sheep and goats 0.02–0.08 mg/kg IV, up to 0.5 mg/kg slowly IV; do not give IM. Extra-label in a food animal — extended withdrawal.

Sheep

• Sedation: Papich 5e: cattle, sheep and goats 0.02–0.08 mg/kg IV, up to 0.5 mg/kg slowly IV; do not give IM. Extra-label in a food animal — extended withdrawal.

Pigs

• Miniature/pet pig — sedation / muscle relaxation: Carpenter Exotic Animal Formulary 6th ed, Table 12-4 (p.664): miniature pigs 0.5–2 mg/kg IM (effective muscle relaxation); 0.1–0.5 mg/kg PO for calming before a car trip/exam. Rarely IV in conscious pigs (venous access difficult). Combine with ketamine.

Buffalo

No buffalo-specific doses are on file, so buffalo are dosed as cattle.

• Sedation: Papich 5e: cattle, sheep and goats 0.02–0.08 mg/kg IV, up to 0.5 mg/kg slowly IV, to effect — cows may become recumbent at 0.5 mg/kg; do NOT give IM. Plumb’s p.382: sedative in calves 0.4 mg/kg IV (Booth 1988).
• CNS hyperactivity / seizures: Plumb’s p.382 (Bailey 1986): 0.5–1.5 mg/kg IM or IV for CNS hyperactivity and seizures. Papich 5e advises against IM use in ruminants — give slowly IV. Extra-label in food animals.

Rabbits

• Sedation / premedication: Plumb’s p.382 (Kaiser-Klingler 2009): rabbits 0.5–2 mg/kg IV or IM for sedation (IV preferred); anaesthesia: diazepam 0.5–1 mg/kg with ketamine 20–35 mg/kg IM or IV. Pre-anaesthetic 1–5 mg/kg IM/IV; seizures to effect IV (Ivey & Morrisey 2000).

Ferrets

• Premedication / sedation: Plumb’s p.382: 1–2 mg/kg IM, may be given with ketamine 10–20 mg/kg (Morrisey & Carpenter 2004); 0.5 mg/kg IM or IV (IV preferred), 0.2 mg/kg if combined with ketamine 2–5 mg/kg (Kaiser-Klingler 2009).

Guinea pigs

• Sedation / seizures: Plumb's p.382 (Adamcak & Otten 2000): guinea pigs 0.5–3 mg/kg IM.

Hamsters

• Sedation / seizures: Plumb's p.382 (Adamcak & Otten 2000): Hamsters/Gerbils/Mice/Rats 3–5 mg/kg IM.

Rats

• Sedation / seizures: Plumb's p.382: 3–5 mg/kg IM.

Mice

• Sedation / seizures: Plumb's p.382: 3–5 mg/kg IM.

Gerbils

• Sedation / seizures: Plumb's p.382: 3–5 mg/kg IM.

Sugar gliders

• Sedation / seizures: Carpenter Exotic Animal Formulary 6th ed, Table 7-3 (p.499): sugar gliders 0.5–2 mg/kg PO/SC/IM. Avoid parenteral injection where possible (use midazolam instead — less irritant). Reverse with flumazenil.

Primates

• Sedation / anxiolysis (monkeys, marmosets): Carpenter Exotic Animal Formulary 6th ed, Table 13-4 (p.693): marmosets/New World monkeys 1 mg/kg IM/IV/PO; chimpanzees/prosimians/lemurs 0.25–0.5 mg/kg IM/IV/PO. Often combined with ketamine for restraint; for IM use midazolam may be preferred (diazepam IM can be painful).

Contraindications

CRITICAL: AVOID chronic ORAL diazepam in cats — IDIOSYNCRATIC FATAL HEPATIC NECROSIS reported 5–11 days after starting therapy (anorexia, lethargy, jaundice, marked ALT/AST/bilirubin rise). Single emergency IV doses are acceptable; chronic oral therapy is not. Baseline + recheck liver values mandatory if cats need any oral course; STOP at first sign of inappetence/lethargy/vomiting. Do not use in cats exposed to chlorpyrifos (potentiates organophosphate toxicity). Significant liver disease. Hypersensitivity. Aggressive patients (may disinhibit aggression). Coma / shock / severe respiratory depression — give very cautiously with cardiovascular/respiratory support ready. RAPID IV in small or neonatal patients can cause hypotension/cardiotoxicity from propylene glycol vehicle — administer slowly over 1–3 minutes. Severe thrombophlebitis if extravasated; flush IV catheter. NEVER intra-arterial. Pregnancy: teratogenic — congenital abnormalities (humans, first trimester); avoid unless benefits clearly outweigh risk.

Species-specific warnings

Dogs: Standard seizure rescue, induction adjunct, anxiolytic. Paradoxical excitement in 5–10% — switch to midazolam if observed.

Cats: NEVER ORAL — idiosyncratic hepatic necrosis (often fatal) reported. Injectable for short-term use (seizures, anaesthesia, appetite stim) is acceptable. Use oxazepam / alprazolam if oral benzo needed long-term.

Horses: IV at 0.05–0.4 mg/kg for foal seizures / sedation. Adult horses: limited oral bioavailability; IV bolus can cause ataxia / recumbency.

Cattle: Cattle sensitive to benzodiazepine sedation — 0.1 mg/kg IV usually sufficient for restraint. Add ketamine for short procedures.

Adverse effects

• Sedation, ataxia (most common across species)
• Dogs: paradoxical CNS excitement (esp. doses ≥0.8 mg/kg), increased appetite, agitation
• Cats: idiosyncratic FATAL hepatic necrosis on chronic oral therapy (anorexia, jaundice, ↑ALT/AST/bilirubin within 5–11 days)
• Cats: behaviour changes — irritability, aberrant demeanour
• Horses: muscle fasciculations, weakness, ataxia at sedating doses; recumbency at >0.2 mg/kg
• Thrombophlebitis with IV use (propylene glycol vehicle)
• Hypotension on rapid IV bolus (propylene glycol)
• Withdrawal phenomena after chronic use — taper slowly

Drug interactions

• CNS depressants (opioids, alpha-2 agonists, anaesthetics, phenothiazines): additive sedation — reduce doses 30–50%
• Cimetidine, fluoxetine, ketoconazole, erythromycin: inhibit hepatic CYP — prolonged diazepam levels
• Phenobarbital / phenytoin: induce metabolism — reduce diazepam effect
• Flumazenil: SPECIFIC ANTAGONIST — 0.01 mg/kg IV reverses benzodiazepine effects
• Cisapride, omeprazole: minor pharmacokinetic interactions
• Alcohol-based parenteral forms: precipitate when mixed with other drugs — give diazepam alone

Pregnancy and lactation

Crosses placenta — neonatal sedation, hypothermia, withdrawal possible. FDA Category D (human, due to oral cleft / congenital malformation signal in epidemiology). Avoid in late pregnancy when alternatives available. Continue if epileptic dam — seizures pose greater risk than the drug.

Monitoring

• Sedation depth — most patients well-controlled at low doses
• Hepatic enzymes (ALT, ALP, bile acids) in cats receiving repeated diazepam (avoid oral entirely)
• Respiratory rate at peak effect — supplemental oxygen if low
• Seizure log (epileptic patients) — diazepam is acute/rescue, not maintenance
• Paradoxical excitement — switch to midazolam or alpha-2 if observed

Toxicity and overdose

Cats: ORAL diazepam can cause IDIOSYNCRATIC HEPATOTOXICITY — acute hepatic necrosis within 2–11 days, often fatal. AVOID oral diazepam in cats; use injectable for short-term (anaesthesia, seizures) only. Profound sedation, ataxia, respiratory depression at high doses (less than barbiturates). Paradoxical excitement / disinhibition in 5–10% of patients (dogs especially). IV bolus too rapid: hypotension, apnoea, cardiac depression (alcohol-based solvent issue).

Management: FLUMAZENIL 0.01–0.02 mg/kg IV is the specific antagonist — titrate to effect. Supportive: airway, oxygen, IV fluids. Activated charcoal if recent oral ingestion. Cats with hepatic necrosis: discontinue, IV fluids, SAMe / silymarin, vitamin K, dextrose for hypoglycaemia, plasma transfusion for coagulopathy — prognosis guarded. Recovery from sedation usually 4–6 h.

Clinical pearls

• Status epilepticus: 0.5 mg/kg IV (dogs), 0.5–1 mg/kg IV (cats) — repeat q5 min × 3 doses; rectal gel 1–2 mg/kg if no IV access
• Pre-anaesthetic / induction adjunct: 0.25 mg/kg IV with ketamine 5 mg/kg in same syringe — "diazepam-ket"
• Appetite stimulant for cats: 0.05–0.4 mg/kg IV — works in <5 min in 70% of cats. NEVER ORAL — fatal hepatic necrosis risk
• Behavioural anxiolysis (storm, fireworks): 0.5–1 mg/kg PO 1–2 h before event (dogs only — never cats)
• Muscle relaxant for orthopaedic / tetanus: 0.5–2 mg/kg PO q8h (dogs)
• Reversal: flumazenil 0.01–0.02 mg/kg IV — useful in oversedation or paradoxical excitement
• NEVER mix diazepam in IV bag with other drugs — propylene glycol solvent causes precipitation
• CATS: ORAL DIAZEPAM = potentially fatal hepatic necrosis — switch to oxazepam, lorazepam, or alprazolam if oral benzo needed
• IM injection painful and erratic absorption — use IV or rectal route

Mechanism of action

Benzodiazepine. Binds the benzodiazepine site of GABA-A receptors, increasing chloride channel opening frequency in response to GABA — enhances inhibitory neurotransmission. Effects: anxiolysis, muscle relaxation, anticonvulsant action, mild sedation, hypnosis at high doses. Active metabolites (nordiazepam, oxazepam, temazepam) extend duration. Does NOT directly bind GABA — needs endogenous GABA to act (ceiling effect, ↓ respiratory depression vs. barbiturates).

Formulations and products

• Tablet 2 mg
• Tablet 5 mg
• Tablet 10 mg
• Injection 5 mg/mL (propylene glycol vehicle)
• Rectal gel 2.5 / 10 / 20 mg per delivery system (Diastat — Plumb’s p.383; dosed per device)

Storage

Tablets: 15–25 °C, dry, protected from light. Injection: 15–25 °C — CONTAINS PROPYLENE GLYCOL + ETHANOL solvent. Do NOT mix in IV bag (precipitation). Rectal gel formulation: 15–25 °C. Schedule IV controlled substance (US) — locked storage.

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 sedatives and anaesthetics

• Alfaxalone
• Azaperone
• Detomidine
• Dexmedetomidine
• Etomidate
• Guaifenesin (GGE)
• Isoflurane
• Ketamine HCl

Frequently asked questions