Why do dogs eat grass?

Honestly, no one knows for sure, but we can make educated guesses. 

Taste

Sometimes the most straightforward answer is the most obvious and should not be discounted. Maybe they like the taste of grass! We know some grass is sweeter than others, and if you pay attention, you will notice that your dog will only eat certain types of grass. So, maybe eating grass for dogs is like us have some sweets. We know they are not healthy, but they taste nice. 

Hydration

Grass does contain much water, and the act of chewing will release some of this water. Plus, when it rains, or there is morning dew, grass can hold many water droplets. So, it is perhaps a good way for a dog to get some extra hydration, and maybe this type of hydration tastes better than tap water. 

Vomiting

The most common assumption is that the dog feels poorly or has an upset stomach. They then eat the grass to be sick. This is a long-held belief and will be true in some cases. As people know, after they have been ill, they do feel a bit better for a while. Or maybe the dog knows it has eaten something it should not have done, which could be poisonous, and what to expel it as quickly as possible. These are both valid reasons and will be the case some of the time. However, I do not think you should presume this is the reason all the time. 

Should you train your dog not to eat grass

It is tempting to train a dog not to eat grass, especially if you have a new carpet you do not want to be ruined. 

I believe you should not train a dog to stop eating grass. It is more important to consider why your dog is eating grass and something you need to do. 

For example, if a dog only eats grass after it has rained, if there is an early morning frost, or when it is spring, and new shoots are growing… then it is likely they are eating grass because they like the taste. They may be sick now and again, but that is not a huge problem and will not be causing them any health issues. 

If they suddenly, out of nowhere, start eating much grass constantly, every time they are let out of the house and show other signs like fatigue, digestive issues, personality changes, then your dog might be poorly. So, it could be worth having them checked out by a Vet. 

All the above applies to just natural grass. If you suspect that the grass has been treated with pesticides and herbicides, then you should stop your dog from eating it. Treated grass like this can be very dangerous to a dog. So, if you know your local park regularly uses weedkillers, or you are walking through a farmer's crop field, then you should be careful with what your dog eats and drinks. 

There are also some house and garden plants that are toxic to dogs. Dogs will generally have a sense of what plants are edible and which ones are potentially harmful to them, but it's not worth the risk. Even if they make your house or garden look pretty, your dog should be your primary concern. This is especially important if you have a puppy, they are always learning, and a lot of this learning involves putting things in their mouths and trying things.