VETINUITY
Pimobendan is dosed at 0.25-0.3 mg/kg PO every 12 hours in dogs (0.5 mg/kg/day total on the label), and extra-label at about 0.625-1.25 mg per cat every 12 hours in cats with heart failure.
Each line is one dose, given every 12 hours, about an hour before food. Round to the nearest quarter tablet.
Vetinuity’s pimobendan dose table: dogs receive 0.25-0.3 mg/kg by mouth every 12 hours (the label’s 0.5 mg/kg/day split into two doses), from ACVIM stage B2 mitral valve disease onward, and cats with heart failure and no outflow obstruction receive an extra-label 0.625-1.25 mg per cat every 12 hours. Run a dog’s weight through the Vetinuity pimobendan dose calculator above to get the per-dose milligrams before choosing tablet strength. This is one of the references inside Vetinuity, the clinical assistant whose builder, Brian Toncray, DVM, works emergency.
| Situation | Dog | Cat | Frequency |
|---|---|---|---|
| MMVD stage B2 (cardiomegaly, no CHF) | 0.25-0.3 mg/kg | Not applicable | PO q12h |
| Preclinical DCM (Dobermans) | 0.25-0.3 mg/kg | Not applicable | PO q12h |
| Stage C congestive heart failure | 0.25-0.3 mg/kg, with furosemide | 0.625-1.25 mg per cat (extra-label) | PO q12h |
| Stage D refractory failure | Up to 0.3 mg/kg q8h (extra-label) | Not established | PO |
In the EPIC trial, dogs with mitral valve disease and cardiomegaly that took pimobendan reached congestive heart failure or cardiac death substantially later than dogs on placebo, which is why the 2019 ACVIM guideline recommends it at stage B2. The earlier QUEST trial compared pimobendan with benazepril in dogs already in heart failure and found longer survival on pimobendan. Neither trial supports starting it at stage B1, where the heart is not yet enlarged.
Chewable tablets come in 1.25, 2.5, 5 and 10 mg; capsules and a US oral solution also exist. Give it about an hour before a meal, because food lowers absorption. The label contraindicates it in hypertrophic cardiomyopathy, aortic stenosis or any condition where raising cardiac output is unsafe; in cats, screen for systolic anterior motion and outflow obstruction before starting. Side effects are uncommon: vomiting, diarrhea, inappetence and, rarely, arrhythmias.
Related: CHF crisis, furosemide, clopidogrel.
Vetinuity's CHF crisis table: furosemide 2 mg/kg IV or IM in dogs, repeated hourly up to about 8 mg/kg in 4 hours or run as a 0.66-1 mg/kg/h CRI, plus oxygen and pimobendan.
Furosemide for acute congestive heart failure is 2 mg/kg IV or IM in dogs and 1-2 mg/kg in cats, repeated hourly to effect, then about 2 mg/kg PO q12h in dogs and 1 mg/kg PO q12-24h in cats at home.
Dobutamine is given as an IV CRI at 2-15 mcg/kg/min in dogs, starting at 2.5-5 and titrated, and at 1-5 mcg/kg/min in cats, where higher rates can cause seizures.
Clopidogrel is dosed at 1.1-4 mg/kg PO once daily in dogs, with an optional one-time loading dose up to 10 mg/kg, and at 18.75 mg per cat PO once daily in cats, the FAT CAT trial dose.
Yes, once it meets stage B2: mitral valve disease with left atrial and ventricular enlargement on echo or radiographs. The EPIC trial showed pimobendan delayed the onset of heart failure or cardiac death in those dogs.
It is extra-label in cats and avoided in cats with dynamic left ventricular outflow tract obstruction, where an inotrope can worsen the obstruction.
Vetinuity explains clinical options with journal citations.
The veterinarian diagnoses and prescribes.