Weight and Body Condition. Obesity is a major health issue, but barring medical complications, it has a reasonable solution: burn more calories than consumed. Regular exercise, like walking, is a good way to burn those excess calories and keep the pounds off.
Joint Health. Immobility is another common health problem. Joints, even old ones, need to work. People and pets get stiff when sedentary for too long, and keeping joints in motion improves their function.
Digestive and Urinary Health. Regular walking helps regulate the digestive tract. Some dogs, like some people, prefer to “go” on a schedule, and providing your dog with routine trips outdoors prevents constipation. Also, when urine sits in the bladder for long periods of time, bladder infections are more likely to occur, so regular emptying keeps this part of the anatomy happy as well.
Of course, it is important to consult your doctor and your veterinarian before embarking on an exercise program.
Mental Health. Dogs do not like to be bored and if you give them something constructive to do, like taking a walk, they may be less likely to do something destructive, like chewing the couch. Walking exercises the mind as well as the body. Watching wildlife, exploring new paths, seeing other people with their pets, and so on, are great mental stimulation for your dog that he just cannot get in the same fenced area all the time. Walking also releases excess energy and helps dogs sleep better at night.