As dog owners of some 25 years and keen gardeners, we have never been troubled by the dreaded yellow patches on our lawn, however since bringing home our most recent labrador (who is a male) we have a constant battle with dead patches. I was always under the impression that this was a condition caused by bitches. I have been told that giving the dog tomato ketchup may cure the problem. We try washing away with water but its difficult to be around every time he piddles. Does anyone have any experience of this. We love him to bits so if it comes to it we may have to astroturf..... Thanks