I would second the notion that it is probably a dog issue. I've also had a past similar issue when i had a riding lawn mower that exhausted onto the grass and if you stopped for an extended period of time would kill a perfect circle like this. I would not say that it would be a grub spot either (a bit TOO dead).

The grass is going to grow like crazy in the early spring regardless of whether you fertilize. Professional grass farmers use their spring application of fertilizer to carry the grass from the time after that initial flush of growth into the summer. In other words they apply after the grass growth slows down. Hence the Memorial Day suggestion by tiemco. Seeding in the spring is not helping matters. You are probably going to water much more frequently to get that seed to sprout. If you would get all your 'densifying' done in the fall, you would be in better shape in the spring. Is your lawn all fescue with no Kentucky bluegrass? KBG would not work much in the shade.

Kutztown! Kutztown is incredibly easy as far as organics go! Albright's Mill in Kempton, right up 737, has organics in plenty for great prices! Cracked corn and corn meal are both available, but I find their corn meal is too finely ground to go through a spreader easily. Sometimes, if it's a light day, they'll specifically rough-grind some corn meal for you. Sometimes they can't. But cracked corn is just fine, if a touch slower. Post October 10th, along with the corn, you can sprinkle a little of the organic compost as well. That'll put the natural fungal populations back into balance (most fungi are helpful and desirable in the soil). Feeding can be either synthetic or organic, but given your nearness to Albright's Mill, it'd be great to go full organic on a smaller or medium-sized lawn. Organics supply more sustained feedings, help sustain the natural biology of the soil, tend to increase worm populations, and overall do a superior job over time--but don't show immediate effects. Figure three weeks until you see any change post an organic feeding. Fifteen pounds per thousand square feet of soybean meal ($14.25 per 50 pound bag the last time I was there in August) will feed the lawn beautifully. Normally, apply it on May 1, August 1, September 1, and October 1. This year, immediately and that's that since we're almost at October 1 anyway. If you'd rather use synthetic, that's fine. Use any high-nitrogen (high first number) fertilizer from your local big box store. This year, immediately. Normal years, Memorial Day, Labor Day, and October 1. (Optimally, when the lawn is no longer growing but still green, feed again with a high-nitrogen synthetic. Dates vary, but usually around Thanksgiving for us, plus or minus two weeks. This particular synthetic app goes even when using organics as it's too cold at that time for organics to process well and the absorption window is very short). There's no specific need to rake, dethatch, or aerate the area, although you can certainly dethatch it if you'd rather look at bare ground than dead grass. Given the date, you're going to be looking at brown grass anyway, so I doubt it much matters. And by spring the stuff will rot away, leaving more blank ground. It's getting way too late to seed in the Kutztown area, although if you apply fungicide this weekend you could probably seed with it. Many fungicides are safe to apply with seed, but check the bag. You'll need to water that seeded area two to three times per day for 5-15 minutes at a shot, however, as the weather is not cooperating in terms of rainfall, moist weather, and normal late September temperatures. It rarely does. Barring that, you can dormant seed the lawn either before our first snowfall (if we get a winter like last year or the year before) or February (if it's like the five years previously with no or very little snow). That won't need watering, and it'll sprout in very late March or into April as the ground temperatures warm. It's the second best time to seed. In either case, newly-grown grass will require irrigation next summer if the weather is drier than it was this year. Once a week, an inch at a time, in those areas will be sufficient to keep it happy until it establishes fully next fall.

Hard to know where to start. For mature grass in your area you should be watering more like 3 hours once every 2 weeks. For new grass seed you should water 5 minutes, 3x per day, for 2-3 weeks until you get 80% germination. Now that you're into September and sitting with this lawn, I think I would go with seed again. June and July was the absolute two worst months of the year for new grass seed. NOW IS THE TIME for new grass seed in the north. Don't wait for spring. Rake up the dead looking grass. It might be alive, but rake through it anyway to get it off the soil. Seed, walk on the seed to press it into the soil, and start watering as above for new seed. All you have to do is moisten the surface of the soil, not saturate it into a muddy mess. If you use Kentucky bluegrass seed, you'll need to keep up that watering for 3 weeks. Then start to back off. By next spring you should be watering once a month. Here's more on how and why. Watering: Deep and infrequent is the mantra for watering. This is for all turf grass all over the place. Deep means 1 inch all at one time. Put some cat food or tuna cans around the yard, and time how long it takes your sprinkler(s) to fill all the cans. Memorize that time. That will be the time you water from now on. My hose, sprinkler and water pressure takes 8 full hours to fill the cans. Your time will likely be less. I like gentle watering. As for watering frequency, that depends on the daytime air temperature. With temps in the 90s, deep water once per week. With temps in the 80s, deep water once every 2 weeks. With temps in the 70s, deep water once every 3 weeks. With temps below 70, deep water once a month. Note that you have to keep up with quickly changing temps in the spring and fall. This deep and infrequent schedule works in Phoenix and in Vermont, so it should work for you. The reason for deep and infrequent is to grow deeper, more drought resistant roots and to allow the soil to dry completely at the surface for several days before watering again. If it rains, reset your calendar to account for the rainfall.