Dogs eating grass is actually quite common (it has been observed in wild dogs, too, and may be completely natural) and this form of pica does not usually cause too many problems. In fact, most veterinarians consider it a normal dog behavior.
Dogs are clever. If every time your dog starts eating grass you rush over making a fuss, they learn pretty quickly that grass equals attention. Even negative attention counts. Over time, this can turn a random behaviour into a regular one.

You should STOP your dog eating grass when you suspect that the grass has been treated with a herbicide. Some chemicals used on lawns and by roads and paths have been treated with weed killers and insecticides which are exceptionally poisonous to a dog. Dogs eat grass.

This particular example perfectly highlights why Treatment For Dogs That Eat Grass is so captivating.
Is grass-eating a physical need for dogs?A Psychological Perspective on the Grass-Eating Behavior of DogsDoes eating grass affect your dogs health?

Pet parents need to be sure that the grass their dog eats does not contain any pesticides, which can poison dogs. If you suspect your dog has eaten grass treated with pesticide, bring them to your local veterinary clinic immediately for treatment.
Reasons Why Dogs Eat Grass. Nutritional Needs: Contrary to popular belief, dogs are not strictly carnivorous. They are omnivores and occasionally require plant matter in their diet. Grass can provide essential nutrients like fiber, which aids in digestion.
Canine Treatment Suggestions That May Job Like Miracle.