In the poultry industry, measures related to combating antimicrobial resistance have accelerated the search for safe and effective alternatives capable of sustaining production while limiting the spread of pathogens in livestock farms. Among these, postbiotics have recently emerged as a promising solution to overcome the use of traditional in-feed additives. Defined as a preparation of inanimate microorganisms and/or their components that confer a health benefit to the host, postbiotics appear to combine biological effects with improved technological stability. Numerous studies have highlighted their beneficial effects on gut morphology, mucus production, immune modulation, microbiota composition and feed conversion ratio. Moreover, several postbiotic formulations exhibit protective effects against pathogens, suggesting a potential role in disease prevention. Overall, current evidence indicates that postbiotics are a valuable tool for improving poultry health, productivity and food safety while reducing reliance on antibiotics. This review summarises the studies on the use of postbiotics in poultry, providing a framework for their documented benefits. It also aims to highlight the limitations associated with their application and the existing knowledge gaps—particularly regarding mechanisms of action, optimal dosages, and methods of administration—in order to support standardisation and ensure reproducibility within the livestock industry.

Myxomatous mitral valve disease (MMVD) is a common cardiac disorder in older small- to 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.