The spots are caused from the high nitrogen in the urine, usually from female dogs. The urine is essentially a highly concentrated fertilizer. The straw-colored spots are usually several inches in diameter, and many spots will have a dark green ring of grass around the spot. One way to remedy this problem is to dilute the urine by giving the dog more water, or watering the area shortly after the dog goes.
The best solution is to train the dog to use a mulched area instead of grass. While some grasses are more able to withstand a single episode, none will withstand repeated treatment from your dog.
