It's the nitrogen in male and female dog urine that burns the grass.
Although there is little difference in the urine between the male and
female (they damage equally given the same grass), the female squats
and leaves a circle in the grass, whereas a male [usually] lifts his
leg and releases the urine onto an object, and the urine runs down
that to the grass. This makes the female spots much more noticable.
Here'a some links that explain it much better:
Burn Baby Burn! Grass Burns from Dog Urine
[an excerpt from the page]
..."Why is it that male dogs don't seem to burn grass like a female dog does?
Female dogs usually squat to urinate, and male dogs (unless they are
squatters) usually urinate on something upright (marking their
territory). This results in a higher concentration of urine left
behind from a female dog, because a male dog's urine is usually
dripping down something, and spread out more thinly. Also adding to
the perception that female dogs are more guilty of burning the grass;
a spot of dead grass in the center of a green lawn is far more obvious
than a small ring around an upstanding object. Isn't that a nice
More [confirming] information:
Tip 85 - Dog urine burning grass
..."Most dog owners are aware that dog urine can damage the grass on
their lawns. This happens because dog urine contains concentrated
amounts of nitrogen which discolours or 'burns' the grass. Although
the earth (and possibly fertilizer) under the grass also contains
nitrogen, the extra amount from dog urine upsets the balance and can
burn the grass. Both male and female dog urine contain nitrogen.
However since female dogs squat and urinate directly on the grass
(instead of urinating ON objects like males usually do,) the problem
is often mistakenly thought to be a female problem..."
Here's a page with more suggestions on what to do:
Entering the search string below into Google will get you a lot more
pages to explore. I hope this helps!
Search terms used at Google:
"dog urine" grass male female