Posted: 08/08/2013 at 21:16
Are you sure the dog isnt repeat offending on the same spot?
The dogs we had while i was a kid always went in the same spots, so the grass never got chance to grow before it was killed again.
You could change the dogs diet slighty, change food type/brands, put more water down, this will help to dilute the excess nitrogen in the dogs urine.
Watering the spot after the dog has done his business will also dilute the urine, although this would require a lot of effort on your part.