What can I put on brown spots on my lawn that are caused by my dogs urine to make them green again?

An effective and free treatment is water. All that you need to do is take a hose and give the affected spot a good watering. The extra water will dilute the nitrogen helping your grass to stay green. If the damage is severe from past urination, just dig up the grass, soak the spot with water, and then put down new grass or new seeds.

I go through this all the time with the neighborhood dogs. My experience is:

Unless there are repeated urination's on the same spot, just keep watering the spot, it will turn green again and be a darker green than the rest of the lawn.

You will probably have to fertilize the entire lawn so you won't have dark green spots where the dog urinated.

i just throw a bunch of seed on the dead spots then wait for him to kill it again, we love the dog, but it's annoying, I know. You can walk your dog more often too, then he won't have as much in the tank. We have about a quarter of the dead spots now.

The urine has killed the grass in those areas. Depending on what type of grass you have, you will probably need to reseed.

1 gallon of soapy water.