Pimobendan: veterinary dose and monograph

At a glance

Drug class

Cardiovascular

Also known as

Vetmedin, Acardi

Species with doses

Dogs, Cats, Rabbits and Ferrets

General dose range

0.25–0.3 mg/kg PO q12h — check the species tables for the indication

Routes

PO

Last reviewed

1 October 2026

Indications

• Canine CHF due to myxomatous mitral valve disease (MMVD/DMVD) — stage B2, C, D
• Canine CHF due to dilated cardiomyopathy (DCM) — first-line in Doberman Pinschers
• Pulmonary hypertension secondary to MMVD (adjunctive)
• Cats with documented dilated cardiomyopathy (extra-label, limited evidence)

Pimobendan 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

• CHF (MMVD or DCM, label): Papich 5e: 0.25–0.3 mg/kg q12h PO (0.125 mg/kg q12h in some dogs on an ACE inhibitor). Plumb’s p.978: label 0.5 mg/kg total daily dose divided into two (not necessarily equal) doses about 12 h apart; 0.4–0.6 mg/kg/day (Lombard); UK label 0.2–0.6 mg/kg/day. Give about 1 h before food.
• Pre-clinical (stage B2) MMVD — EPIC dose: Same dose as for CHF — Papich 5e 0.25–0.3 mg/kg PO q12h; Plumb’s p.978 label 0.5 mg/kg/day divided. Use in pre-clinical MMVD with cardiomegaly is based on later trial data (not described in the reference editions used).
• Refractory stage D heart failure: Plumb’s p.978 (Atkins 2009 ACVIM consensus): some panelists raise pimobendan to 0.3 mg/kg PO three times daily in refractory stage D failure — no consensus; outside the approved label, so obtain informed client consent.

Cats

• DCM (extra-label, limited evidence): 1.25–1.5 mg per cat PO q12h (Rishniw 2005). Papich 5e p737 confirms 1.25 mg/cat q12h PO (≈0.1–0.3 mg/kg). NOT for HCM — the predominant feline cardiomyopathy. Confirm DCM/myocardial failure on echo before use.

Rabbits

• Dilated cardiomyopathy / valvular disease: Carpenter's 6th ed (Rabbit cardiovascular table): 0.1–0.3 mg/kg PO q12–24h (up to 0.2–1 mg/kg) — inodilator for DCM/valvular disease.

Ferrets

• Dilated cardiomyopathy / mitral valve disease: Carpenter's 6th ed (Ferret cardiopulmonary table): 0.25–1.25 mg/kg PO q12h — inodilator for DCM or degenerative mitral valve disease, the common ferret cardiomyopathies.

Contraindications

CONTRAINDICATED in hypertrophic cardiomyopathy (HCM), aortic stenosis, or any condition where increasing cardiac output is harmful — including most cats with HCM. Use cautiously with uncontrolled cardiac arrhythmias (may worsen ectopy). Not evaluated in dogs <6 months, dogs with congenital heart defects, diabetes mellitus, breeding/pregnant/lactating bitches. Calcium-channel blockers (verapamil, diltiazem) and beta-blockers (propranolol, atenolol) can blunt pimobendan's inotropic effect. May worsen mitral valve lesions on long-term therapy — monitor with serial echo.

Species-specific warnings

Dogs: First-line for MMVD stage B2 and stage C, and DCM. Give on empty stomach. Always combined with ACE-I; furosemide + spironolactone added in symptomatic patients.

Cats: Emerging evidence of benefit in DCM and non-obstructive HCM with CHF. HOCM (obstructive HCM): historically CONTRAINDICATED — consult cardiologist before use. Dose 0.625–1.25 mg/cat PO q12h.

Adverse effects

• Inappetence / poor appetite (~38% of dogs in 56-day field trial)
• Lethargy (~33%)
• Diarrhoea (~30%)
• Dyspnoea, ascites, pleural effusion (often disease- not drug-related)
• Increased frequency of ventricular ectopy / atrial fibrillation in some dogs
• Azotaemia (often disease- and concurrent-diuretic-related)
• Worsening mitral valve lesions on histology (Chetboul 2007) — monitor with serial echo

Drug interactions

• Other positive inotropes (digoxin, dobutamine): additive — but pimobendan is generally first-line; digoxin reserved for atrial fibrillation control
• Beta-blockers (atenolol, carvedilol): theoretical antagonism of inotropic effect; clinically often combined in DCM
• ACE inhibitors (enalapril, benazepril): synergistic — standard CHF protocol
• Furosemide / spironolactone: routine combination — quadruple therapy (pimobendan + ACE-I + furosemide + spironolactone) for stage C MMVD
• NSAIDs: caution — renal compromise risk if hypotension or dehydration
• Other vasodilators (amlodipine): additive hypotension risk

Pregnancy and lactation

Not commonly used in pregnant patients (most cardiac disease is in adult / senior animals). Crosses placenta. Safety in pregnancy not established. Use only if cardiac status of dam mandates.

Monitoring

• ECG / blood pressure at start and after dose adjustments
• Respiratory rate at rest (target <30/min on stable therapy)
• Body weight, appetite, exercise tolerance — track at each recheck
• Renal function (BUN, creatinine) every 3–6 months — combined with ACE-I + furosemide risks azotaemia
• Cardiac biomarkers (NT-proBNP, troponin I) at 3–6 month intervals
• Echocardiography every 6–12 months — LV size, LA:Ao ratio, function

Toxicity and overdose

Wide therapeutic index. Acute overdose: reflex tachycardia, hypotension, vomiting. Possible arrhythmias (especially in DCM with pre-existing rhythm disturbance). Cats with HOCM (hypertrophic obstructive cardiomyopathy): pimobendan can worsen outflow obstruction — historically contraindicated, though recent data suggest safety in non-obstructive HCM with CHF.

Management: No specific antidote. Supportive: IV fluids (cautiously — avoid volume overload in cardiac patients), beta-blocker (esmolol, atenolol) for tachyarrhythmias, anti-emetic for vomiting. Monitor ECG, blood pressure. Recovery usually within 12–24 h.

Clinical pearls

• Dogs MMVD stage B2 (asymptomatic with LV enlargement): 0.25–0.3 mg/kg PO q12h — EPIC trial showed 15-month delay in CHF onset
• Dogs MMVD stage C (symptomatic CHF): 0.25–0.3 mg/kg PO q12h alongside ACE-I + furosemide + spironolactone (quadruple therapy)
• Dogs DCM: 0.25–0.3 mg/kg PO q12h — improves survival
• Cats DCM / non-obstructive HCM with CHF: 0.625–1.25 mg PO q12h (per cat dose, not weight-based) — emerging evidence of benefit
• Cats HOCM (obstructive HCM): controversial — historically contraindicated due to outflow obstruction; consult cardiologist
• Give on empty stomach — food reduces absorption ~30%
• Pimobendan is generally NOT used as monotherapy — pair with ACE-I in stage B2 and add furosemide ± spironolactone in stage C
• Liquid suspension available for compounding flexibility in small / picky patients

Mechanism of action

Benzimidazole-pyridazinone "inodilator". Two complementary actions: (1) Calcium SENSITISER — increases myocardial contractility (positive inotrope) by enhancing troponin-C affinity for calcium without raising intracellular Ca²⁺ or myocardial oxygen demand; (2) Phosphodiesterase III INHIBITOR — vasodilation (arterial + venous) reduces preload and afterload. Net effect: increased cardiac output and reduced cardiac workload, especially valuable in mitral valve disease and DCM. Demonstrated to prolong pre-clinical disease-free interval in dogs with stage B2 MMVD (EPIC trial).

Formulations and products

• Vetmedin chewable tablet 1.25 mg
• Vetmedin chewable tablet 2.5 mg
• Vetmedin chewable tablet 5 mg
• Vetmedin chewable tablet 10 mg
• CorForce (Indian Immunologicals (IIL), Hyderabad) — 5 mg, Uncoated chewable tablet

Storage

Chewable tablets: 15–25 °C, dry, protected from light. Oral suspension: refrigerate (2–8 °C) after reconstitution, discard 14 days after opening.

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.

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• Phenylephrine
• Procainamide
• Propranolol
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• Ramipril

Frequently asked questions