2. Top dog for the go-getter: Retired racing Greyhound
A racing Greyhound retires at the tender age of 2 to 5 years, but will live as long as 14. They lived their racing lives in kennels, so they’re accustomed to behaving when unattended for long periods. They need a good jog once a day, but their exercise can double as yours. Just make sure they’re always on a leash when they’re not in an enclosed area — even the retired ones can run up to 45 miles per hour, and you can only hit about 12 to 15.