Abstract
IMPORTANCE: Cognitive dysfunction syndrome (CDS) is an age-related neurodegenerative disorder increasingly recognized in dogs and cats because of their longer lifespans and stronger human–animal bonds. Behavioral changes, disorientation, and altered sleep–wake cycles reduce quality of life and complicate management. OBSERVATIONS: Recent research highlights the utility of behavioral tools, such as the Canine Dementia Scale, Canine Cognitive Assessment Scale, and Canine Cognitive Dysfunction Rating Scale, for early detection and monitoring. Blood biomarkers, particularly neurofilament light chain and glial fibrillary acidic protein, show strong associations with disease severity and progression in dogs, highlighting diagnostic and prognostic potential, though standardization remains limited. Nutritional interventions supported by reviews suggest benefits from medium-chain triglycerides, omega-3 fatty acids, and S-adenosyl methionine, while outcomes for antioxidant combinations vary with dose and study quality. Environmental enrichment and structured activities enhance resilience, and when combined with dietary strategies, they produce synergistic benefits on cognition and neuropathology. However, variations in diagnostic criteria, small sample sizes, and inconsistent outcome measures hinder comparability across studies, challenges more pronounced in feline CDS owing to scarce evidence. CONCLUSIONS AND RELEVANCE: By consolidating behavioral, biomarker, nutritional, and environmental evidence, this review provides a clear multimodal framework for diagnosis and management of CDS in companion animals. The findings highlight substantial progress in canine medicine and the urgent need for validated feline-specific tools and longitudinal, standardized trials. Advancing CDS research improves veterinary care and strengthens its translational value as a spontaneous model for human dementia.