Check the teeth for wear, tartar, and missing teeth
Look at the eyes for cloudiness or age-related changes
Examine the coat for graying, thinning, or rough texture
Assess muscle tone and body condition
Observe activity level, energy, and mobility
Watch for stiffness, arthritis, or slower movement
Compare size and breed-specific aging patterns
Review veterinary records if available
Ask a veterinarian for a dental and physical exam
Use X-rays or bloodwork if a more accurate estimate is needed