Generally all dogs will eat grass and there is no known reason for them not to.
If a dog has an ailment it will seek out a natural remedy. For a gassy or upset stomach, grass, it seems, may do the trick. When ingested, the grass blade tickles the throat and stomach lining; this sensation, in turn, may cause the dog to vomit, especially if the grass is gulped down rather than chewed.
Eating from the mowed grass however suggests that either it is creating an easier salad to consume or the lawn may have growing in it certain types of weeds or grass or clover that are appealing to the dogs senses especially when chopped up releasing juices and odor.
So it really is nothing to be concerned about but a sudden increase in grass eating could signal an intestinal ailment that might need veterinary attention. Eating grass could lead to accidental ingestion of pesticides, herbicides, or chemicals that have been used to treat your (or your neighbor's) yard so that is one precaution you should take before allowing your dog to eat grass..