Why Do Dogs Eat Grass? And Should You Be Worried?

It’s a question almost every dog owner has asked at some point:

“Why does my dog eat grass?”

You’re out for a walk or watching your dog in the garden, and suddenly they start munching on grass like they’re part cow. It can seem strange, especially if it ends with them being sick. But is this something to be concerned about?

First, Is It Normal for Dogs to Eat Grass?

Yes! Grass eating is very common in dogs. In fact, a study published in Applied Animal Behaviour Science found that 68–79% of dogs eat grass regularly. Most of them were otherwise healthy and didn’t show signs of illness beforehand.

So, while it can look odd to us, it’s actually a normal behaviour for many dogs.

So...Does It Mean My Dog Feels Sick?

Not necessarily.

Some people believe dogs eat grass to make themselves vomit when they feel unwell. While this might happen occasionally, it’s not the most common reason. The same study mentioned earlier showed that only around 9% of dogs vomited after eating grass, meaning the majority did not eat grass as a way to be sick.

But is My Dog Missing Something in Their Diet?

It’s possible, but unlikely if your dog is eating a balanced, complete diet.

There’s no strong evidence to suggest dogs eat grass because of a nutritional deficiency (like needing more fibre or minerals) although some behaviourists and vets suggest it might play a small role for some individuals.

If your dog is on a good quality diet and is otherwise well, grass eating is probably not about missing nutrients.

Then Could It Be Behavioural?

Absolutely.

For many dogs, grass eating is simply a behaviour that feels good or helps them self-soothe, especially if they’re feeling bored, anxious or in need of sensory enrichment. If a dog is very stressed by something around them, they might start biting big chucks of grass, rather than just grazing. It's definitely worth keeping an eye on, so that you can be aware of how your dog feels.

Grass might:

• Feel interesting in the mouth

• Smell appealing - you may notice your dog search for particular types of grass, rather than eating it all

• Be part of a foraging instinct

• Work as a displacement behaviour (keeps them busy if they feel unsure or worried, kind of us like going on our phones!)

  
  

When to Be Concerned

Grass eating is generally harmless, but there are a few times you may want to take a closer look:

• Your dog is vomiting frequently after eating grass

• They’re eating large amounts of grass every day

• They seem distressed, uncomfortable or in pain before or after eating it

• You suspect the grass has been sprayed with pesticides or chemicals

What You Can Do

If your dog enjoys eating grass and it doesn’t make them unwell, you don’t need to stop it entirely. But if it's becoming excessive or compulsive, try the following:

• Add enrichment to walks and the home (sniffing, foraging, puzzles)

• Monitor patterns (e.g., does it happen more when they’re tired, stressed or bored?)

• Offer safe alternatives like dog friendly chews or scatter feeding

• Speak to a force free, qualified behaviourist or behaviour consultant if it feels obsessive or tied to anxiety

  
  

Need help understanding your dog’s behaviour or building a calmer, happier daily routine? I specialise in helping anxious and reactive dogs feel safe and supported. You can always book a free discovery call to see how I can help.

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