Dog doors are not a substitute for proper exercise for most dogs or puppies and should never be an excuse for leaving them alone for long periods of time. (all-about-puppies.com)
These dogs do not do well when left alone for long periods of time. (pawster.com)
The best way to maintain a garden that is safe for dogs to hang out in is to make sure you don't leave them alone in the garden for long periods of time. (ipupster.com)