Clinical Value of Serum Cardiac Troponin I, Trimethylamine N-Oxide (TMAO), and Galectin-3 in Canine Myxomatous Mitral Valve Degeneration: A Preliminary Study

Myxomatous mitral valve disease (MMVD) is a common cardiac disorder in older smallto medium-sized dogs. Diagnosis and staging are primarily based on echocardiography; however, circulating cardiac biomarkers have gained increasing interest because they are rapid and easily measurable. In this context, the investigators’ aim was to study the clinical value of galectin-3 (Gal-3) and trimethylamine N-oxide (TMAO), in dogs affected by MMVD, in comparison to cardiac troponin I (cTnI), a well-established biomarker of myocardial injury, and echocardiography. Twenty-two dogs were classified as healthy controls or affected by MMVD and staged according to American College of Veterinary Internal Medicine (ACVIM) guidelines. Serum concentrations of Gal-3, TMAO, and cTnI were measured and compared among groups. No significant differences in serum Gal-3 concentration were detected among groups (p = 0.955). In contrast, TMAO levels were significantly higher in both asymptomatic and symptomatic dogs compared with healthy controls (both p < 0.001). Serum cTnI showed limited sensitivity, with increased values observed only in some symptomatic dogs. Despite study limitations, including small sample size and demographic differences among groups, these preliminary findings suggest that TMAO could be a potential biomarker associated with MMVD development and progression; however, further studies are needed to confirm this association.