Abstract
IMPORTANCE: Lifestyle factors have emerged as critical modulators of aging and health outcomes in dogs and cats. Beyond genetic and biological determinants, modifiable behaviors—such as nutrition, physical activity, and environmental exposures—play a substantial role in shaping healthspan. On the other hand, veterinary care often underutilizes these levers because of limited awareness, fragmented guidelines, and a lack of integrative frameworks for geriatric management. OBSERVATIONS: This narrative review examines the impact of lifestyle on the aging process in companion animals, synthesizing current scientific evidence and clinical insights. The key domains examined included dietary quality, physical activity, environmental stressors, social interaction, sleep, and preventive care, each of which affects systemic aging patterns and disease vulnerability. Special emphasis was placed on sedentary behavior, sarcopenia, obesity, toxic exposures, cognitive decline, and caregiver burden. Species-specific considerations are addressed, and the opportunities for veterinarians to intervene through practical, evidence-based strategies are highlighted. CONCLUSIONS AND RELEVANCE: A paradigm shift toward proactive, lifestyle-centered veterinary care is supported by reframing aging as a dynamic and modifiable process. Promoting individualized, preventive strategies can improve the functional longevity, mitigate frailty, and support quality of life in senior pets. Veterinarians are uniquely positioned to translate lifestyle science into meaningful clinical outcomes across the lifespan.