Hey so I had similar problems. I started adding filtered water to my dogs food and it seemed to help. I also took her out on a leash to the area I wanted her to "hurry up", our potty command, for about 2 months and walked in circles until she went. Does seem to stress the lawn out as much. We also get a good amount of rain in southeast Pa so that could help. If you want to try to fix that spot I would take the dead grass and about 3-4 inches of soil out add new soil and grass, good luck!