Wait 3 weeks after Rabies and Distemper vaccine is given (their last shot). The reason to wait 3 weeks is to give the vaccine time to get completely into the dogs system. I know it's a long wait and we want to get our sweet lil bundles of joy out and about, but it is for the well being of the puppy.
I personally am not in favor of letting a un-vaccnated puppy in my own fenced in yard due to other critters visiting the area. Squirrels, mice, moles, birds all carry disease, fleas and other things that can harm a un-vaccnated puppy. Always better to be safe then sorry
Last shots are usually at 14 to 16 weeks old