They can help determine the appropriate dosage and monitor your response to supplementation
Palka, J., Oscilowska, I
For laboratory preparation, a suitable solvent is required for reconstitution
(See the list of studies, linked here.) The EPIC trial's report concluded: "Chronic oral administration of pimobendan to dogs with echocardiographic and radiographic evidence of cardiomegaly [enlargement] secondary to MMVD, in the absence of concurrent cardiovascular medication, results in the prolongation of the preclinical period, and is safe and well tolerated." Note that, as big a step as the EPIC trial took for promoting pimobendan, its investigators still emphasized the necessity of both "echocardiographic and radiographic [x-ray] evidence" that the dog's heart is enlarged due to MVD
The Journal of Nutrition, Volume 54, Issue 4, December 1954, Pages 571577, Halick, J.V