Diazepam

Diazepam is a benzodiazepine with anticonvulsant, anxiolytic, sedative and centrally mediated muscle-relaxant activity. Its principal emergency application is rapid seizure control. It is also used in balanced anesthesia and selected behavioral or muscle-spasm disorders. Active metabolites contribute to its effects, and the clinical response varies with species, route and concurrent drugs.

Group

Benzodiazepine

Mechanism of Action

Diazepam binds the benzodiazepine site on susceptible GABA-A receptor complexes and acts as a positive allosteric modulator. In the presence of GABA, it increases chloride-channel opening frequency and strengthens inhibitory neurotransmission. The resulting reduction in neuronal excitability suppresses seizure activity and contributes to anxiolysis, sedation and muscle relaxation. Hepatic metabolites retain benzodiazepine activity and can extend the overall effect.

Dose Rates

Dog

Use / stage	Dose	Route	Schedule	Instructions
Preanesthetic	0.5 mg/kg	IV
Status epilepticus	0.5 mg/kg	IV	As needed
Status epilepticus	0.5–1 mg/kg	IN	As needed
Status epilepticus	1 mg/kg	RECTAL	As needed
Seizure infusion	15 mcg/kg/min	IV	Continuous	Reduce by 50% if excessive adverse effects. The source’s approximate 1 mg/kg/hour equivalence is rounded; 15 mcg/kg/min equals 0.9 mg/kg/hour.
Behavior modification	0.5–2 mg/kg	PO	Every 4–6 h
Situational anxiety	0.55–2.2 mg/kg	PO	Every 8–12 h
Urethral sphincter relaxation	0.2 mg/kg	PO	Every 8 h
Urethral sphincter relaxation	0.5 mg/kg	IV
Metronidazole neurotoxicity	Reference only	IV		Study protocol used an average 0.43 mg/kg once IV, followed by the same dose orally every 8 hours for 3 days; this is a reported study average rather than a universal exact dose.

Cat

Use / stage	Dose	Route	Schedule	Instructions
Preanesthetic	0.5 mg/kg	IV
Status epilepticus	0.5 mg/kg	IV	As needed
Status epilepticus	0.5–1 mg/kg	IN	As needed
Status epilepticus	1 mg/kg	RECTAL	As needed
Seizure infusion	15 mcg/kg/min	IV	Continuous	Reduce by 50% if excessive adverse effects. The source’s approximate 1 mg/kg/hour equivalence is rounded; 15 mcg/kg/min equals 0.9 mg/kg/hour.
Appetite stimulation	0.2 mg/kg	IV		Short-term use; other appetite stimulants are preferred.
Behavior modification	1–4 mg/animal	PO	Every 12–24 h	Historical regimen; prolonged oral therapy carries potentially fatal hepatic risk.
Situational anxiety	0.2–0.4 mg/kg	PO	Every 12–24 h	Oral diazepam in cats can cause fatal idiosyncratic hepatic necrosis.
Urethral sphincter relaxation	0.5 mg/kg	IV

Cattle

Use / stage	Dose	Route	Instructions
Sedation	0.02–0.08 mg/kg	IV	Slow injection; doses up to 0.5 mg/kg have been reported, with recumbency likely in cattle at the higher dose.
Seizures and CNS hyperactivity	0.5–1.5 mg/kg	IM, IV
Tranquilization	0.55–1.1 mg/kg	IM

Sheep

Use / stage	Dose	Route	Schedule	Instructions
Sedation	0.02–0.08 mg/kg	IV		Slow injection; doses up to 0.5 mg/kg have been reported, with recumbency likely in cattle at the higher dose.
Tranquilization	0.55–1.1 mg/kg	IM

Goat

Use / stage	Dose	Route	Instructions
Sedation	0.02–0.08 mg/kg	IV	Slow injection; doses up to 0.5 mg/kg have been reported, with recumbency likely in cattle at the higher dose.
Bermuda-grass toxicosis tremors	0.8 mg/kg	IV
Appetite stimulation	0.04 mg/kg	IV	Offer food immediately; effect may last 45 minutes.

Horse

Use / stage	Dose	Route	Schedule	Instructions
Seizures	0.1–0.4 mg/kg	IV		Source also cites an initial total 50–100 mg per horse; titrate clinically.
Foal seizure infusion	Reference only	IV		Foals: 1–3 mg/hour, an absolute infusion rate not supported by the current per-kg infusion schema.

Ferret

Use / stage	Dose	Route	Schedule	Instructions
Sedation	1–2 mg/kg	IM
Sedation	0.5 mg/kg	IM, IV		IV preferred in this alternative regimen.

Rabbit

Use / stage	Dose	Route	Instructions
Sedation	2–10 mg/kg	IM
Sedation	0.5–2 mg/kg	IM, IV	IV preferred in this alternative regimen.
Preanesthetic medication	1–5 mg/kg	IM, IV
Anesthesia with ketamine	Reference only	IM	Diazepam 0.5–1 mg/kg plus ketamine 20–35 mg/kg, IM or IV as a combined anesthetic regimen.

Hamster

Use / stage	Dose	Route	Schedule	Instructions
Sedation	3–5 mg/kg	IM

Gerbil

Use / stage	Dose	Route	Schedule	Instructions
Sedation	3–5 mg/kg	IM

Mouse

Use / stage	Dose	Route	Schedule	Instructions
Sedation	3–5 mg/kg	IM

Rat

Use / stage	Dose	Route	Schedule	Instructions
Sedation	3–5 mg/kg	IM

Guinea Pig

Use / stage	Dose	Route	Schedule	Instructions
Sedation	0.5–3 mg/kg	IM

Hedgehog

Use / stage	Dose	Route	Schedule	Instructions
Anesthesia with ketamine	Reference only	IM		Diazepam 0.5–2 mg/kg plus ketamine 5–20 mg/kg IM for longer anesthesia.

Pig

Use / stage	Dose	Route	Instructions
Seizures and CNS hyperactivity	0.5–1.5 mg/kg	IM, IV
Tranquilization	0.55–1.1 mg/kg	IM
Tranquilization	5.5 mg/kg	IM	Distinct alternative; posterior ataxia may develop before recumbency.
Premedication for pentobarbital	8.5 mg/kg	IM	Maximal effect approximately 30 minutes; reduces subsequent pentobarbital requirement.

Bird

Use / stage	Dose	Route	Schedule	Instructions
Sedation	0.5–2 mg/kg	IV, IM		Pet birds through medium parrots; not a validated general dose for large parrots or raptors.
Adjunctive analgesic sedation	0.5–2 mg/kg	IV, IM		Use with an analgesic; diazepam itself does not provide analgesia.

Indications

Emergency treatment of seizures, cluster seizures and status epilepticus in dogs and cats.
Anesthetic co-induction, premedication or adjunctive sedation in selected veterinary patients.
Adjunctive control of muscle spasms or excessive muscle tone, including selected tetanus or toxin-associated syndromes.
Treatment of selected anxiety-related behavioral disorders in dogs and cats; response is indication-dependent.
Short-term intravenous appetite stimulation in selected cats, an historical and less commonly used application.

Contraindications

Impaired hepatic function
Avoid long-term oral use in cats because potentially fatal hepatic necrosis occurs.

Interactions

Adsorbs to soft PVC infusion bags and tubing.
Mixing with aqueous fluids can cause precipitation.

Adverse effects

Sedation, ataxia and paradoxical excitation
Dependence and withdrawal
Phlebitis; painful IM or SC injection

Toxicity

Excessive CNS and respiratory depression; hepatic necrosis can occur idiosyncratically in cats.

Preparations

Preparation	Form	Strength	Route
Diazepam 2 mg	Tablet	2 mg / tablet	PO
Diazepam 5 mg	Tablet	5 mg / tablet	PO
Diazepam 10 mg	Tablet	10 mg / tablet	PO
Diazepam oral solution 5 mg/mL	Oral Liquid	5 mg / mL	PO
Diazepam injection 5 mg/mL Intranasal and rectal use are extralabel emergency administration of the injection formulation.	Injection	5 mg / mL	IV, IN, RECTAL

Monitoring and Administration

Avoid IM use because absorption is unpredictable and injections painful.

Protect from light; hard plastic syringes differ from soft PVC containers. Monitor respiration and cardiovascular function during emergency treatment.