My sympathies, my lawn has the same problem. It gets a LOT of sun, but they say you should only water deeply once every 5 days. Once I did that, I got these brown spots. I believe the roots are still alive.

dog urine

Looks like Red Thread to me, at least in some areas. Was the lawn tall and wet earlier this year?

I got similar problem to you. I've done soil test, added lime like test said, and my grass is still dying. I have no idea what to do. I've started water it more frequently like 3 times per week and now I have another problem to deal with crabgrass... Just get drunk and wait for winter

Based on the pictures you sent, I would say that it is Pythium Blight and is easily treated by applying additional nitrogen to those areas that are most affected. This is a very common problem during periods of heat and high humidity

Also, make sure your mower blade is sharp as a dull blade will aid in the spread of disease.

Lastly, only water early in the day so that your lawn has a chance to dry out before nightfall.

Best Regards,
Byron

Stack,
I'm in the same situation. Bought the place last year and have the same symptoms in Wakefield. If you pull out a few blades of grass you can see red blades and spots on the grass. Looks like fungi, dollarspot, red thread, rust etc. Scotts has a fungi treatment that is supposed to help but you may need a few applications to make it work and its not pet friendly. Some people recommend fertilizer to grow it out but if the roots are dead then its too late. We had so much rain this year and early humidity it just breeds fungus. New grass seed has build in fungus immunity so aerating and overseeding in the fall with a good seed may put us on track helping with drainage and growing a more tolerate turf. I also had grubs even though I put down grub control in spring. I hear end of June to July is best time when beetles are laying eggs but that's another story. I tried the Scotts fungus control last week and Summer turf builder this week, next I'll spread dimes and quarters and see how that looks.

The damage is from your dog's urine.
Look at the pic.
It is specifically where you rope up your dog.
There isn't much to do about that, unless you train your dog to only go in a specific area of the yard.

>"Based on the pictures you sent, I would say that it is Pythium Blight"

Why not point out to the OP the obvious mycelium that you must see, that makes you come to this conclusion, Byron.