Too many stupid answers to one decent question.

The green patches are not from dog urine (that kills the grass and turns it
brown). There's a high nitrogen content in the soil underneath the grass.
What you have are earthworms giving castings (earthworm poop) to the soil
underneath which enriches the soil. To encourage more earthworms in the
nearby grass, try a cheap solution to increase their population (works also
in garden beds). If you or someone near you drinks coffee, save the coffee
grounds (not the filter paper!) and sprinkle these around the darker green
patches. When the earthworms emerge at night, they'll consume the grounds
and begin tunneling in the soil nearby. Works great.
"Turfinator" wrote in message
news:GsqZc.296424$gE.204790@pd7tw3no...
I have many darker green patches about 1 foot wide all over my back yard
and
a few in my front. These patches have grass that looks healthy but it
grows
much faster than the rest of my lawn. There is no dead grass or brown
grass
just dark green patches that have seemed to multiply on my lawn. I first
thought this may be due to our new female retriever and the nitrogen in
her
urine but I have also seen this in the front yard and on a boulavard down
the street. Any ideas?