Buspirone: veterinary dose and monograph

At a glance

Drug class

Veterinary drug

Also known as

Buspar, Buspin, Ansial

Species with doses

Dogs, Cats, Horses and Birds

General dose range

0.5–1 mg/kg PO q8–12h — check the species tables for the indication

Routes

PO

Last reviewed

1 October 2026

Indications

• Feline anxiety; fear/anxiety-based urine spraying/marking (especially in multi-cat tension)
• Increasing confidence in timid/fearful cats
• Generalised anxiety (adjunct to behaviour modification)
• Canine anxiety (less commonly; SSRIs/clomipramine usually preferred)

Buspirone 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

• Anxiety (adjunct): Papich 5e: 1 mg/kg PO q12h, or 2.5–10 mg per dog q12–24h. Plumb’s p.168: 1 mg/kg q8–24h for mild anxiety; 1–2 mg/kg q12h (Siebert); global anxiety 0.5–2 mg/kg q8–12h, 2–4 weeks to effect (Horwitz); 10–15 mg per dog q8–12h for more severe anxiety or storm phobia (Overall).

Cats

• Anxiety / urine marking / timidity: Papich 5e: 2.5–5 mg per cat q12h, increasing to 5–7.5 mg twice daily in some cats (0.5–1 mg/kg q12h). Plumb’s p.168: 0.5–1 mg/kg PO q8–12h (Overall; Virga); urine marking 2.5–7.5 mg per cat q12h (Levine). Allow 1–4 weeks for effect; pair with behaviour modification; may increase assertiveness in multi-cat homes.

Horses

• Anxiety (behavioural): Papich 5e: 100–250 mg per horse q24h PO (about 0.5 mg/kg).

Birds

• Anxiety / behavioural disorder: Carpenter's 6th ed (Bird psychotropic table): 0.5 mg/kg PO q12h — non-sedating anxiolytic; used in a case to control paradoxical anxiety from clomipramine.

Contraindications

Severe hepatic or renal impairment. Concurrent MAO inhibitors / selegiline (serotonin/hypertensive reaction) and caution with other serotonergic drugs. Known hypersensitivity. Multi-cat households where increased confidence might worsen aggression dynamics (assess carefully).

Species-specific warnings

Cats: As a timid treated cat gains confidence, inter-cat aggression can occasionally increase — assess household dynamics and combine with behaviour/environmental modification.

Adverse effects

• Usually well tolerated and non-sedating
• Occasional increased affection/restlessness; GI upset
• Possible INCREASED inter-cat aggression as a timid cat gains confidence
• Rare bradycardia/tachycardia

Drug interactions

• MAO inhibitors / selegiline: hypertensive/serotonergic reaction — avoid
• Other serotonergic drugs (SSRIs, TCAs): additive serotonergic effects — caution
• CYP3A4 inhibitors (azoles, macrolides): increased buspirone levels
• No significant additive sedation (non-sedating)

Pregnancy and lactation

Limited data; avoid in pregnancy unless clearly needed.

Monitoring

• Anxiety/behaviour response over 1–4 weeks (set owner expectations — gradual onset)
• Multi-cat household dynamics (treated cat may become more confident/assertive)
• GI tolerance; no sedation expected
• Use within a behaviour-modification plan

Toxicity and overdose

Wide safety margin; overdose causes GI upset, restlessness or mild CNS effects (and rare cardiovascular changes). It is non-sedating and non-addictive, so the toxicity profile is benign compared with benzodiazepines. The notable behavioural "adverse effect" is occasionally worsened inter-cat aggression as a timid cat becomes bolder.

Management: No specific antidote. Supportive care; effects are generally mild and self-limiting. Manage serotonin-related signs supportively (cyproheptadine if a serotonergic reaction). Decontaminate large recent ingestions.

Clinical pearls

• A NON-sedating, non-addictive feline anxiolytic — great for chronic anxiety and fear-based urine marking, and it can turn a timid cat more confident
• Give it 1–4 weeks to work (like an SSRI) and combine with behaviour modification/environmental change
• A key cat advantage: no benzodiazepine-style sedation/dependence and none of oral diazepam's rare feline hepatotoxicity
• In multi-cat homes, watch the dynamic — the newly confident cat may assert itself and shift aggression patterns

Mechanism of action

A partial agonist at presynaptic and postsynaptic serotonin 5-HT1A receptors (with some dopaminergic activity), modulating serotonergic neurotransmission to reduce anxiety WITHOUT the GABA-mediated sedation, muscle relaxation or dependence of benzodiazepines. The anxiolytic effect develops gradually as serotonergic adaptation occurs (days to weeks), similar to the delayed onset of SSRIs.

Formulations and products

• 5 mg tablet
• 10 mg tablet
• Buspin / Ansial — 5 / 10 mg tablet, Tablet (human-label)

Storage

Tablets: 15–30 °C, dry, protect from light.

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 hormones, emergency drugs, supplements and other drugs

• Bethanechol
• Bromhexine
• Budesonide
• Buserelin
• Butaphosphan + Cyanocobalamin
• Cabergoline
• Calcitriol
• Calcium Borogluconate (IV Calcium)

Frequently asked questions