Better Safe Than Sorry
The best way to keep your Pug safe is to have a fenced in yard or an area of your yard especially for your Pug. A fence will help keep your Pug safe from getting hit by cars, attacked by larger dogs, kidnapped by strangers or getting lost.
Anytime you are outside with your Pug and it is not in a fenced area, you will need to be there to supervise your Pug and keep them on a leash to protect them. Be sure that you can get two fingers comfortably between the collar and the neck of your Pug. When walking your Pug, it's best to use a harness that doesn't wrap directly around the neck. Pugs are prone to collapsing trachea, so using a regular collar for walks (especially if your Pug walks ahead of you and/or pulls) can put unnecessary pressure on this area.
Pugs do NOT make good swimmers. They are heavier in the front, causing them to sink. If you plan on taking your Pug with you on your boat or to another water activity, please have them wear a doggy life jacket. Even if you keep them in the very shallow water along the shoreline, please supervise them 100% of the time.
Pugs are very susceptible to eye injuries. Their eyes are close to the front of their faces and are oversized. Pugs have been blinded from running into sharp corners of tables, chairs or other furniture. Pug owners should always evaluate their home to protect their Pug's eyes. Avoid "rough housing" with your Pug's head area or rough play with other pets, as the Pug's eyes are vulnerable.