The injury on the left is from dog urine, which kills the grass in the soaked areas, leaving circular patches of dead turf. As seen on the right, green grass is growing around the outer edges of the patches. This rapidly growing grass is the result of extra nitrogen contained in the urine. Usually only the grass blades are killed and the turf is capable of recovering. Soaking new spots with water may speed recovery of the grass. Keeping pets off of the lawn is the best way to avoid this problem, but unfortunately this is not always possible or practical.
