Eating grass when your dog's stomach is upset is quite instinctive, natural behavior that is often also observed in cats. However, eating grass isn't necessarily a sign of digestive upset; certain dogs simply enjoy nibbling on some grass.
It's not completely understood why they may enjoy this activity, but it's assumed it derives from an instinctual need to add some roughage and minerals to their diets.
Dogs who ingest grass because they have an upset stomach will often ingest it quickly, and if they have no access to grass, they may be seen licking the carpet and floors. Other accompanying signs include drooling, repeated gulping and lip licking.
Dogs suffering from bilious vomiting syndrome have a tendency to want to go out first thing in the morning to consume grass. After eating the grass, many dogs with digestive upset will vomit and the vomit will typically contain the grass along with fluids.
Once the vomiting episode is over, many dogs will appear to feel better almost immediately. However, it should be considered that in some cases, despite the effort to eat grass, dogs may be suffering from a disorder that requires vet attention. For instance, grass eating may be seen in some dogs as they develop the initial signs of bloat, a life threatening condition that commonly affects deep chested dogs.
The bottom line for dogs who eat grass is determining whether they do so for digestive upset or the simple pleasure of nibbling on some greens. Some owners report that after the addition of low-sodium string beans to their dogs foods or after feeding a high-fiber diet, their dog's cravings for grass reduced.
Dogs who eat grass persistently and show signs of digestive problems should see the vet to rule out any digestive disorders. Something important to consider if your dog eats grass, is that the grass consumed does not contain any pesticides or fertilizers.