Game of Bones field guide

Why Is My Dog Eating Grass?

Grass-eating is one of the most common — and most misunderstood — dog behaviors. Here's what the research actually says.

Behavior · 4 min read · Updated 16 July 2026 · Game of Bones team

It's More Normal Than You Think

Studies observing domestic dogs found that grass-eating is extremely common — some surveys report over 70% of dogs do it regularly — and that only a small minority show any sign of illness beforehand or vomit afterward. In other words: for most dogs, eating grass is simply normal behaviour, not a sign that something is wrong.

THE RESEARCH

What Studies Actually Found

~70%

of dogs eat grass on a regular basis

<10%

show signs of illness beforehand

~25%

vomit after eating grass — most don't

The Leading Theories

Dietary fibre-seeking: Wild canid ancestors consumed the stomach contents of herbivore prey, which included partially digested plant matter. Grass-eating may be a leftover instinct to supplement fibre.
Taste and texture: Some dogs genuinely just seem to enjoy the taste and mouthfeel of fresh grass, especially young, tender shoots — the same way dogs enjoy crunchy vegetables.
Boredom or habit: For dogs who spend a lot of time in a yard or on long walks, grazing can become a repetitive, almost habitual behaviour, similar to idle snacking.
Mild nausea relief: A minority of dogs do eat grass specifically when they feel nauseous, and vomiting afterward provides genuine relief. This is real, but it is the exception, not the rule.

When It's Worth Paying Attention

Occasional grass-eating with no other symptoms is not something to worry about. It becomes worth mentioning to a vet if it's accompanied by: frequent vomiting, sudden onset in a dog who never used to do it, weight loss, lethargy, or a marked increase in frequency or urgency about seeking out grass specifically.

Is It Actually Dangerous?

The grass itself is rarely the problem. The real risks are usually what's on the grass — pesticides, herbicides, or fertiliser used in parks and gardens. Avoid letting your dog graze on lawns you know have been recently treated with chemicals, and be cautious in public parks where you can't verify what's been sprayed.

Should You Try to Stop It?

If your dog eats grass occasionally, is otherwise healthy, active, and eating normally, there's generally no need to intervene. If it's excessive or compulsive, redirecting with a chew or a walk, and ensuring your dog's regular diet has adequate fibre, is a reasonable first step — alongside a chat with your vet if the behaviour changes suddenly.

Simple guideline: Occasional, calm grass-grazing on clean, untreated grass = normal dog behaviour. Frantic, repeated, or sudden grass-eating alongside other symptoms = a reason to call your vet.

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