Does he have an upset stomach?
Does he like it?
Does he have a nutritional deficiency?
Is he bored?
There are many theories as to why dogs eat grass. You can search the internet and find almost any answer you are looking for, including that it settles an upset stomach, it makes them vomit, they have a nutritional deficiency, and that they are bored. In my experience, dogs seek out fresh food, and because it's abundant in their backyard, they eat it. Let me explain.
We feed our dogs an abundance of processed food. Most people feed their dogs kibble from a bag. Kibble has been processed (mixed and heated to high temperatures) and then has many vitamins and minerals added during the process. If your dog is eating just kibble, they never receive any fresh vitamins, minerals, or fiber. This poses quite a problem for digestion and for the ability of the gut to work properly.
A dog's gastrointestinal system is similar to ours. Could you imagine only eating the same processed food every single day? You, too, would be deficient in important vitamins, minerals, and fiber. Fresh food is very important to build the bacteria in the gastrointestinal system. This is where a healthy microbiome comes from.
There has been much research on the health of the microbiome in humans and dogs. What we have discovered is that feeding fresh foods (especially vegetables that provide fiber) helps build a healthy microbiome. Fresh foods are typically easier to digest and provide fresh vitamins and minerals, which are necessary for many body processes.
I know kibble costs less than feeding fresh food. If you do choose to feed kibble, I recommend reducing the kibble by 25% and adding in fresh food to include lean cooked meats, and raw or cooked vegetables (avoid onions and garlic), and I recommend slow cooking (in a crockpot) to preserve vitamins and nutrients. If you do this, your dog may give up eating grass altogether. If you are wondering, yes, I am a huge proponent of feeding "real food" to our dogs. I believe it is necessary.
Our dogs seek out grass because they need fresh food, nutrients, and fiber. The problem with eating grass is much of our grass is chemically treated. These chemicals are not healthy for your dog to eat. If you do not treat your grass with chemicals, it is completely safe for your dog to eat the grass.
What if they vomit? Well, that is probably because they "binged" on grass and overate. Has your dog ever drank a ton of water and vomited? Sometimes our dogs do not regulate their will to eat well, and if they eat (or drink) too much, the stomach will reject it.
Dogs munching on grass is a complex behavior rooted in their instinctual and dietary needs. It's a fascinating reminder of their natural inclinations and our responsibility to provide a balanced diet. By feeding more fresh foods, or blending fresh foods with their regular kibble, we might just satisfy their craving for greens, ensuring they stay healthy and content.
Stay tuned for more information on "what do I feed my dog," this has been a very controversial subject and will be explored soon!
That was a great explanation. Thanks!