Stage B1 CKCS require no treatment and monitoring every 12 months, with the goal of detecting progression to B2 before clinical signs develop. Animals

Stage B2 is defined by cardiac enlargement and warrants pimobendan initiation. The 2019 ACVIM consensus guidelines form the basis of current treatment recommendations, and 67% of surveyed practitioners correctly initiate pimobendan as monotherapy at the B2 stage. Animals The ACVIM guidelines recommend breed-specific radiographic reference values when available — for CKCS, the breed-specific vertebral heart score reference is 10.6 ± 0.5 vertebrae, which is higher than the non-breed-specific reference of 9.7 ± 0.5, making breed-specific thresholds essential to avoid over-staging. Veterinary Radi…

Echocardiographic staging in CKCS should incorporate LA/Ao ratio, left atrial anteroposterior diameter normalized to body weight (LADn), and left atrial volumes. CKCS in ACVIM B1 already demonstrate increased LADn and increased left atrial volumes compared to stage A dogs, indicating atrial remodelling begins at the earliest detectable stage of disease. Research in Vet… LA enlargement is an adverse prognostic factor, and B1 dogs with LA enlargement have poorer outcomes than B1 dogs without it. Journal of Vete… Both active and passive left atrial emptying fractions are useful indexes for detecting atrial dysfunction, which becomes particularly evident in symptomatic (stage C) dogs. Research in Vet…

Pulmonary hypertension (PH) screening is warranted in CKCS with MMVD, as CKCS are more likely to develop PH from MMVD than dogs of other breeds. ACVIM stage, LA/Ao ratio, and mitral E wave velocity are all independently associated with PH development, and PH development is associated with worse MMVD severity by ACVIM stage. Journal of Vete…

Stage C treatment requires a loop diuretic combined with pimobendan as the only evidence-based drug combination. Only 48% of surveyed practitioners prescribed this correct combination for chronic stage C management; 19% of practitioners prescribed two loop diuretics simultaneously, which is not evidence-based. Animals Sixteen different drug combinations were reported in practice for stage C, reflecting substantial clinical disagreement at this stage. Animals

Renal function monitoring is an essential component of ongoing management in all stages. Serum creatinine has limited sensitivity in MMVD dogs because small-breed dogs have reduced skeletal muscle mass and dogs with severe MMVD frequently develop cardiac cachexia, both of which suppress creatinine independent of glomerular filtration rate — creatinine does not rise until GFR has declined by 75%. Journal of Vete… Renal dysfunction is a negative prognostic factor in MMVD dogs, and dogs with elevated creatinine have shorter survival times. Journal of Vete…

Morphotype influences echocardiographic severity in CKCS and should inform risk stratification. Dogs with shorter head length and nose length have more severe regurgitant jet size, and dogs with a more pronounced head stop angle have thicker anterior mitral valve leaflets. A brachycephalic morphotype is associated with more severe regurgitant jet size and valvular characteristics linked to the most severe forms of MMVD. Veterinary Scie…

CKCS with concurrent symptomatic syringomyelia have significantly smaller left ventricular and left atrial dimensions — LVIDDN 1.45 (IQR 1.30–1.50) and LA/Ao 1.20 (IQR 1.10–1.28) — compared to CKCS with asymptomatic syringomyelia (LVIDDN 1.60 [1.50–1.90], LA/Ao 1.40 [1.20–1.75]), which should be accounted for when interpreting echocardiographic staging in dogs with both conditions. Journal of Vete…

Would you like to go deeper on the specific echocardiographic cutoffs that define the transition from B1 to B2 in CKCS, including the MINE score 2 risk stratification thresholds?