Asian Journal of Current Research

Molecular biomarkers have progressively displaced descriptive clinicopathological interpretation as the principal means by which veterinarians detect, stage and monitor disease in dogs and cats. This narrative review synthesises the peer-reviewed literature on renal, cardiac, inflammatory, pancreatic, infectious, oncological and genomic biomarkers in small animal medicine, with the aim of identifying which biomarkers now possess sufficient analytical and clinical validation to influence practice, and which remain investigational. Evidence was drawn from PubMed/MEDLINE, Scopus, Google Scholar, CAB Abstracts and the Cochrane Library, supplemented by citation tracking, and was appraised for study design, sample size, reference-standard comparison and reproducibility. Symmetric dimethylarginine has accumulated the strongest validation among renal biomarkers, detecting a reduction in glomerular filtration rate of less than twenty per cent earlier than serum creatinine in a controlled longitudinal cohort, although large-scale concordance data indicate that mild elevations require cautious interpretation. Cardiac natriuretic peptides and troponin I show high sensitivity for structural heart disease but limited ability to discriminate cardiac from respiratory dyspnoea when used alone. Acute phase proteins, principally C-reactive protein in dogs and serum amyloid A in cats, offer reliable inflammatory monitoring but lack disease specificity. Pancreatic lipase immunoreactivity remains the most sensitive serum test for moderate-to-severe pancreatitis yet performs poorly in mild and chronic disease. Molecular diagnostics based on polymerase chain reaction and next-generation sequencing have transformed infectious disease detection and are beginning to support liquid biopsy approaches in oncology, although clinical validation in cats and dogs lags behind analytical proof of concept. Genomic panel testing has matured into a practical breeding and diagnostic tool but carries interpretive limitations related to variant penetrance and cross-breed extrapolation. Across all domains, the evidence base is constrained by small, single-centre cohorts, inconsistent reference intervals, limited external validation and an almost complete absence of formal biomarker-approval pathways specific to veterinary medicine. Future priorities include multicentre validation studies, standardised pre-analytical protocols, multimodal biomarker combinations and clearer regulatory frameworks for translating omics-derived candidates into clinical assays. The findings support cautious, mechanism-aware integration of molecular biomarkers into small animal practice rather than uncritical adoption.