You sound just like my neighbor, who’s nice gentle black lab would not hurt anyone. One day I was in my garage, and heard a low growl. I turned around to see that gentle black lab crouched down low baring his teeth and growling at me ( not the first time either ) I hit it in the head with a shovel...told the neighbors, and to this day the dog still runs loose....
You must have mis-read my posts. First off, I would never let ANY dog run loose. Second, if my dog did get loose and act as this dog did to you, it would be gone immediately. Third, I would never own a lab in the city anyway, because I would not be willing to take that responsibility.
Next time use a heavier shovel...Or steel rake, tines down...stay safe...goat granny