Pimobendan timing and dosing for a Cavalier in Stage B2 M...

Excellent question. Your staging of this Cavalier as ACVIM Stage B2 based on an LA:Ao of 1.8 is spot on, and this is precisely the point to initiate therapy to delay the onset of congestive heart failure.

The evidence from the EPIC trial is clear on this. Starting pimobendan now can extend the asymptomatic period by an average of 15 months, which is a significant improvement in quality of life for your patient.

Dosing and Administration:
* Dose: Initiate pimobendan at 0.25-0.3 mg/kg PO every 12 hours.
* Timing: This is critical. Pimobendan must be given on an empty stomach, at least one hour before feeding. Food can decrease its bioavailability by up to 30%, so adherence to this timing is essential for maximal efficacy.

Monitoring Plan:

Baseline SRR: Instruct the owner to begin monitoring and recording the sleeping respiratory rate (SRR) at home now. Establishing a baseline while the patient is stable is invaluable. The target is to remain consistently under 30 breaths per minute. This is their most sensitive tool for detecting progression to Stage C.

Recheck: I would schedule a recheck, including an echocardiogram, in 6 months to reassess chamber dimensions and function. If clinical signs develop sooner, of course, see them immediately.

No Diuretics: Reinforce with the owner that we are treating heart disease to delay heart failure. Furosemide is not indicated at this stage and would be counterproductive.

You are on the perfect track with this case. Starting pimobendan now is the standard of care and will make a real difference for this dog. Let me know if you have any further questions.