We have reviewed all those urban legends regarding urine dog spots. Now, let's cover what you can do.
• Train the dog to use a non-turf area in the landscape, such as a area covered with mulch or gravel, or select a location where dog spotting will not become an aesthetic problem and damage can be tolerated. This is the ONLY sure solution for the problem!
• Always provide adequate water for your pet; increased water consumption will dilute urine, reducing the potential for turf injury.
• While the addition of salt, garlic, tomato juice and other “home remedies” to your pet’s food can increase water consumption (thus diluting their urine), your veterinarian should always be consulted before doing so. The increased salt intake can cause problems for older dogs, as well as for those with heart or kidney conditions.
• Except for the addition of water to a dog’s food, no additive or supplement should be fed to your pet without first consulting with your veterinarian.
Certain additives may increase a dog’s water intake, but can have detrimental and unintended consequences for its health.
Source: Colorado State University Extension for this information (December 2010 - Fact Sheet #553).