I have an area of my lawn where the grass is very lush. It gets plenty of water and food and has always looked great all year. now, all of a sudden, I have dead spots through out this area. not huge spots like a dog would leave, but like someone splashed drops of something toxic all over it. some are the size of a quarter, some are the size of your hand. does anyone have an idea what I am up against?
Thanks for any help.

Dori, there are so many things that can go wrong with a lawn, to point to one particular reason is chancy, there' usually more than one that gives the same result.

You specifically rule out a dog doing what you see. Howcum?
Do you have doag....you evidently know the damage they can do...but I think you have the wrong idea how much damage they can do.
My lawn, right now, is showing exactly what you are seeing; small areas of brown caused by my two dogs peeing in the general area.
It would be nice if they could 'go' in the exact same spot, time after time, but they don't..they like to sniff around and then they decide whether to let loose.
My spots are as you describe, small..smaller...and smallest.
Small being about 4" across...smallest 2"...and in a general area going down the driveway.

You are doing the right thing--watering your lawn, feeding it the right stuff...no feeding in summer..making a lush lawn is the best defence.

Have you noticed these spots getting larger --as though on their own. That could point to a disease or a fungus attack.
Have they appeared at this time in past years?

In spring, such happenings can be thought to be under the turf...grubs.
Grubs do come usually August/September as larvae before settling back down later on. But they usually don't do damage widespread--spots here and there. The adult grub is a beetle. You could lift the turf there and see if you see any grubs. I doubt that's your problem.

Honestly, I think its dogs and if so, those spots are easily remedied by simply taking a plug from the edge of a garden or from where it wont be noticed, and fill in the spots.
Later on with the return of cooler weather, would be the best time.
Other than that...dig them out, a little topsoil, then overseed the areas.
In spring, those areas would fill in anyway.
Don't go overboard with your watering....too much water causes short roots...and short roots at this time, will fall to the heat.
One inch per week...rain notwithstanding.
Don't fertilize during summer heat...that too sets up short roots, poor grass which then is killed by sun and heat.

There are of course, many ailments that do attack lawns but unless you say you know its not dogs, then I'll stop now and let someone else suggest.

Dori it might help to know what type of grass your having this problem with !

Kimmsr usualy drops in early of the mourning and will most likely offer you some excelent advice . His adviced is generaly short and to the point !

Since you already ruled out dog urine these ould be most anything from a species of grass that just up and died to maybe, possibly one of the lawn diseases that stick when grass is under stress. What is the grass mixture you have? Is there a possibilty that some annual rye grass got planted there?

I have no idea what sort of grass it is. It is what survives up here in Minnesota. I did just spread some grub killer on it and am hoping for the best. the area is too widespread for dog pee I think, scattered spots over a 10 by 15 area. they do seem to be getting a little larger, as they were not there early this spring. starting noticing them about three weeks ago. I guess I will hope for the best and see what happens this fall. if it stops, and/or if the dead areas come back.
Thanks for all the ideas.