Is dog poop bad for grass?

Cow manure works as fertilizer because a cow's diet is plant matter that has already been broken down. A dog's diet is protein-heavy, which produces waste with a much higher nitrogen concentration and a low pH. Grass roots under that load dehydrate, and you get the classic pattern: a dead center with a darker green ring around it where the nitrogen diluted enough to feed the lawn instead of burning it.

Timing matters more than most people expect. In Northern Virginia's humid summers, waste stays moist and keeps leaching into the soil for days. In winter it freezes in place and dumps everything at once during the first thaw — which is why yards often look worst in late February even though nothing new happened.

The fix is removal frequency, not lawn treatment. Yards on weekly pickup rarely show burn spots because nothing sits long enough to leach. Yards cleaned monthly almost always do. If you already have spots, rake the dead material out, water the area deeply to flush the salts, and reseed in fall.