# Bethanechol: veterinary dose and monograph

> Bethanechol is a veterinary drug. A cholinergic (muscarinic) agonist that stimulates smooth-muscle contraction of the BLADDER (detrusor) and gut — used to improve emptying in DETRUSOR ATONY / hypotonic bladder (e.g. Indications include detrusor atony / hypotonic bladder — improve emptying (after relieving any obstruction); lower-motor-neuron bladder dysfunction (with sphincter management); GI hypomotility / ileus (adjunct, less common). This monograph lists 5 reference doses for dogs, cats, cattle and horses, each with route, frequency and source, plus meat and milk withdrawal periods for food animals.

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

## At a glance

- **Drug class:** Veterinary drug
- **Also known as:** Urotone, Urivoid, Duvoid
- **Species with doses:** Dogs, Cats, Cattle and Horses
- **Routes:** PO, SC
- **Last reviewed:** 1 October 2026

## Indications

- Detrusor atony / hypotonic bladder — improve emptying (after relieving any obstruction)
- Lower-motor-neuron bladder dysfunction (with sphincter management)
- GI hypomotility / ileus (adjunct, less common)

## Bethanechol 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

*Bethanechol doses for dogs*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Detrusor atony (improve emptying) | 2.5–25 mg per dog PO q8h (small 2.5 mg, medium 5 mg, large 15 mg) | PO | q8h | — |
| Dysautonomia (symptomatic) | 1.25–7.5 mg per dog PO daily to q8–12h, or 0.05 mg/kg SC q12h | PO | q8–24h | — |

- Detrusor atony (improve emptying): Papich 5e: 5–15 mg per dog q8h PO (2.5 mg small, 5 mg medium, 15 mg large dogs); SC possible but oral preferred. Plumb’s p.149: 5–25 mg total PO q8h (Bartges; Dickinson); 5–15 mg q8h (Lulich). Ensure the urethra is patent and relaxed first; start low (cholinergic effects).
- Dysautonomia (symptomatic): Plumb’s p.149: 2.5–7.5 mg divided q8–12h (Sisson); 1.25–5 mg once daily (Willard); 0.05 mg/kg SC q12h, increased slowly (O’Brien).

### Cats

*Bethanechol doses for cats*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Detrusor atony | 1.25–7.5 mg per cat PO q8–12h | PO | q8–12h | — |

- Detrusor atony: Papich 5e: 1.25–5 mg per cat q8h PO. Plumb’s p.149: 1.25–7.5 mg per cat PO q8h (Osborne; Bartges). Combine with a urethral relaxant if there is functional obstruction.

### Cattle

*Bethanechol doses for cattle*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Caecal dilation/dislocation (medical therapy) | 0.07 mg/kg | SC | q8h | 2 days | Withdrawal NOT established — treat as extra-label |

- Caecal dilation/dislocation (medical therapy): Papich 5e: 0.07 mg/kg SC. Plumb’s p.149 (Meylan 2004): 0.07 mg/kg SC three times daily for 2 days, only in mildly affected cattle without torsion; go to surgery if no improvement in 24 h. Obtain a FARAD withdrawal.

### Horses

*Bethanechol doses for horses*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Bladder atony (detrusor stimulation) | 0.025–0.075 mg/kg | SC | q8h | — |

- Bladder atony (detrusor stimulation): Plumb’s p.149: 0.025–0.075 mg/kg SC q8h, adjusted per patient (Jose-Cunilleras & Hinchcliff); oral dose is about 10× — 0.25–0.75 mg/kg PO 2–4 times daily (Schott & Carr); foals 0.4 mg/kg PO 2–3 times daily. Papich 5e: 0.025 mg/kg SC once. ARCI Class 4.

### Buffalo

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

*Bethanechol doses for buffalo*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Caecal dilation/dislocation (medical therapy) | 0.07 mg/kg | SC | q8h | 2 days | Withdrawal NOT established — treat as extra-label |

- Caecal dilation/dislocation (medical therapy): Papich 5e: 0.07 mg/kg SC. Plumb’s p.149 (Meylan 2004): 0.07 mg/kg SC three times daily for 2 days, only in mildly affected cattle without torsion; go to surgery if no improvement in 24 h. Obtain a FARAD withdrawal.

## Contraindications

Urethral/GI mechanical OBSTRUCTION or increased outflow resistance without concurrent sphincter relaxation (bladder rupture risk). Recent bladder/GI surgery (suture line). Hyperthyroidism, bradyarrhythmia, asthma/bronchospasm, and peptic ulceration (cholinergic effects). Known hypersensitivity.

## Species-specific warnings

> **Caution:** Cats: Often functional urethral obstruction (spasm) coexists — pair with a urethral relaxant and confirm patency before using bethanechol to avoid bladder rupture.

## Adverse effects

- Cholinergic (SLUD) signs: salivation, lacrimation, urination, defecation, vomiting/diarrhoea
- Abdominal cramping
- Bradycardia, hypotension
- Bronchoconstriction; risk of bladder rupture if used against obstruction

## Drug interactions

- Anticholinergics (atropine): antagonise the effect (and are the antidote for overdose)
- Other cholinergics/anticholinesterases: additive cholinergic toxicity
- Ganglionic blockers: severe hypotension
- Beta-blockers: additive bradycardia

## Pregnancy and lactation

Limited data; use only if clearly needed.

## Monitoring

- Bladder emptying / residual urine volume (efficacy)
- Cholinergic side effects (SLUD, GI, heart rate) — titrate dose
- CONFIRM a patent/relaxed urethra before and during use (rupture risk)
- Combine with an alpha-blocker (e.g. prazosin) / skeletal-muscle relaxant if sphincter tone is the obstruction

## Toxicity and overdose

Overdose produces a cholinergic crisis — profuse SLUD signs (salivation, lacrimation, urination, defecation), vomiting/cramping, bradycardia, hypotension, bronchospasm and weakness. The most serious clinical hazard is using it against an obstructed outlet, risking bladder rupture.

Management: Antidote: ATROPINE (anticholinergic) reverses the muscarinic cholinergic effects — give for significant cholinergic toxicity. Supportive care (fluids, airway/bronchospasm management). Ensure no outflow obstruction.

## Clinical pearls

- The "squeeze" drug for an atonic bladder — it strengthens detrusor contraction to improve emptying
- NEVER squeeze against a closed door: rule out/relieve obstruction (and add urethral relaxation, e.g. prazosin/diazepam) before/with bethanechol, or you risk bladder rupture
- Atropine is the antidote for cholinergic overdose (SLUD signs)
- Start low and titrate — cholinergic GI/cardiovascular effects are the dose-limiter

## Mechanism of action

A synthetic muscarinic (cholinergic) agonist resistant to acetylcholinesterase, so it produces a sustained stimulation of muscarinic receptors on smooth muscle — increasing detrusor (bladder) and gastrointestinal smooth-muscle contraction and tone. It is relatively selective for the urinary and GI tracts with comparatively modest cardiovascular/nicotinic effects, which is why it is favoured for bladder atony.

## Formulations and products

- 5 mg tablet
- 10 / 25 mg tablet
- Urotone / Urivoid — 5 / 10 / 25 mg tablet, Tablet (human-label)

## Storage

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

## 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 Bethanechol for dogs?

Reference doses for Bethanechol in dogs: 2.5–25 mg per dog PO q8h (small 2.5 mg, medium 5 mg, large 15 mg) PO q8h (Detrusor atony (improve emptying)); 1.25–7.5 mg per dog PO daily to q8–12h, or 0.05 mg/kg SC q12h PO q8–24h (Dysautonomia (symptomatic)). Confirm against the label and the patient before use.

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

Reference doses for Bethanechol in cats: 1.25–7.5 mg per cat PO q8–12h PO q8–12h (Detrusor atony). Confirm against the label and the patient before use.

### What is the dose of Bethanechol for cattle?

Reference doses for Bethanechol in cattle: 0.07 mg/kg SC q8h for 2 days (Caecal dilation/dislocation (medical therapy)). Confirm against the label and the patient before use.

### What is the withdrawal period for Bethanechol?

Cattle, SC (Caecal dilation/dislocation (medical therapy)): Withdrawal NOT established — treat as extra-label. Follow the product label and national regulations where they differ.

### When should Bethanechol not be used?

Urethral/GI mechanical OBSTRUCTION or increased outflow resistance without concurrent sphincter relaxation (bladder rupture risk). Recent bladder/GI surgery (suture line). Hyperthyroidism, bradyarrhythmia, asthma/bronchospasm, and peptic ulceration (cholinergic effects). Known hypersensitivity.

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

Cholinergic (SLUD) signs: salivation, lacrimation, urination, defecation, vomiting/diarrhoea; Abdominal cramping; Bradycardia, hypotension; Bronchoconstriction; risk of bladder rupture if used against obstruction.

## Sources

- Plumb's Veterinary Drug Handbook
- Merck Veterinary Manual, 11th edition
- 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.