When considering the question ‘Why does my dog eat grass?’ many dog guardians may think that it always means their dog has an upset stomach or has eaten something that disagrees with them, and is trying to induce vomiting. While it is true that some dogs will eat grass and then vomit soon afterwards, only around 25% of the dogs that munch on the lawn or verge will actually vomit. Those that do tend to do so quite quickly, and usually seem to have swallowed longer blades of grass not chewed up. It is thought these irritate the throat and trigger the vomiting. If a dog eats grass, vomits, and then seems to be fine, they have probably taken care of the problem. If they seem to be retching but cannot actually vomit, or keep repeating the grass/vomit cycle repetitively, they should have a check-up from their veterinary surgeon.
What about the other 75% of grass eating dogs? Why do they eat grass? There are a few theories. Some think that the grass provides extra fibre; some also think that the dogs choose to eat grass to fill a need for some other nutrient missing from their diet. Dogs fed on a quality, nutritionally balanced diet may also eat grass as well meaning that something missing from the diet is not always the answer. Dogs are not obligate carnivores as cats are, they do not have to eat just meat – dogs can in fact survive and thrive on vegetarian and vegan diets, although as many dogs would choose meat when it is offered as an option some question the ethics of these diets. What it does mean is that eating vegetable matter, including grass, is not inherently dangerous to dogs. If you have a dog that eats grass, check to ensure that nothing, especially any chemicals, used in your garden could be harmful to them.
Boredom can be a factor in some grass-eating dogs, who chew and eat as something to do. This can be rectified by some research into canine enrichment and finding fun and interesting things that dogs can do – and humans and dogs can do together – to stave off boredom.
Some dogs will eat grass because they like it! One of my previous dogs was a confirmed grazer, despite a good diet that he enjoyed. Out walking, he would browse the field verges for choice stalks and had a favoured patch of grass in a corner of the garden at home that he would visit several times a week for a snack. Particularly in spring, grass can be sweet and fresh with new growth, and it seems some dogs just like the taste.