It is a scene every dog owner knows: you are on a walk, and suddenly your dog stops to furiously munch on a patch of grass. It can be confusing (and a little gross if they throw it up later), but rest assured, you are not alone. Grass eating, or 'pica', is one of the most common behaviors observed in domestic dogs.
Theory 1: The 'Tummy Ache' Solution
The most popular theory is that dogs eat grass to induce vomiting when they feel nauseous. The grass blades tickle the throat and stomach lining, triggering a purge. While this does happen, studies show that fewer than 25% of dogs actually vomit after eating grass, and only 10% show signs of illness beforehand. So, while possible, it is likely not the only reason.
Theory 2: The Ancestral Scavenger
Your dog's wild ancestors (wolves) didn't just eat meat. They consumed the entire prey animal, including the stomach contents of herbivores, which were full of plant matter. Modern dogs are omnivores, not carnivores. Eating grass might simply be an evolutionary instinct to add roughage and fiber to their diet, aiding in digestion.
Theory 3: Boredom or Taste
Sometimes, the answer is simple: they just like it. Fresh spring grass has a specific texture and sweetness that some dogs enjoy. For others, it is simply something to do. If your dog is left alone in the backyard for hours, grazing gives them an activity to pass the time.
Is It Safe?
Generally, eating grass is harmless. However, the *grass itself* isn't the danger—it is what is *on* the grass. Fertilizers, pesticides, and herbicides can be toxic to dogs. Additionally, lawns frequented by other dogs can harbor intestinal parasites (like hookworms) that transfer via soil. If your dog is a 'grazer,' make sure they are on a regular deworming schedule and avoid lawns that have been chemically treated.
