Table 2 Staging system for MMVD according to the ACVIM MMVD consensus

A

Dogs at a high risk but currently have no disorder

B1

Asymptomatic dogs having no cardiac remodeling

B2

Asymptomatic dogs with left atrial and ventricular enlargement

C

Dogs with clinical signs of heart failure due to MMVD

D

Dogs with end-stages MMVD, in which clinical sings of heart failure are refractory to the standard treatment