There are many options available to dog owners who struggle with the effects of their urine on their grass. It is of note that female dog urine is generally stronger than males, so this may provide context on what measures you will take, in order to help your situation.
Here are some solutions:
Some have found the combination of dishwashing liquid and water to be effective in diluting dog urine. Measure out roughtly 1 part mild dishwashing liquid with 8 parts of water. Then apply generously to the damaged area.
Visit your local pet store. Usually these will sell plastic dog markers that have components which attract dogs to them. Make sure you mark an area that you do not mind your dog going to in order to urinate. In our personal opinion, this is not the best option, since many markers have low consumer ratings—so make sure you do your research to find a good one!
Some grasses are less sensitive than others when it comes to dog urine. So while looking for a grass that is suitable for your region, also make sure that it can remain strong after being hit with dog urine—like Zoysiagrass. Still though, it would be good to dilute any spots that you see your dog repeatedly going to.
Synthetic grass will not become damaged by the effects of dog urine… but it might become smelly if you do not keep it clean. There are products that absorb dog urine and take away the smell that you hate, such as "Zeofill." In addition, you can also use certain products with your water sprayer to deodorize your lawn. When you search for the right synthetic grass, look specifically for those designed for dogs. These allow for proper drainage into the soil when your dog urinates on it.
Some companies, like "Porch Potty," specialize in special grass trays that attract your dog to them—instead of your lawn. Some have options that allow you to use synthethic grass, or real grass, which can be shipped to you on a regular basis. The more expensive versions also have built-in sprinkler systems that rinse away dog urine to a designated location, immediately after the dog has left the tray.
Go to your local pet store and usually they will supply special supplements, like "Grass Saver," that you can add to your dogs diet. These supplements are sometimes in "treat" form and they neutralize the high levels of nitrogen in their urine.
This is the least expensive option and probably the best—plus you get to spend quality time with your dog and you both will get some exercise. Yes… walk your dog!