Why Do Dogs Eat Grass?
Many dogs occasionally nibble on grass. This behaviour may seem concerning, but it’s usually normal. Let’s explore what researchers think is happening.
Theories & evidence
There is no single, proven reason why dogs eat grass. Veterinary behaviourists speculate that dogs may eat grass to induce vomiting, soothe an upset stomach, add fibre to their diet or simply because they enjoy the texture. Research suggests that dogs typically eat grass before meals and less often after eating, hinting that hunger or instinct may play a role.
Do dogs eat grass to make themselves vomit?
Contrary to popular belief, most dogs do not vomit after eating grass. Studies show that fewer than 25 % of dogs vomit after eating grass. Therefore, vomiting is unlikely to be the primary reason for grass consumption.
Is grass eating dangerous?
Occasional grass eating is generally harmless, but there are risks. Lawns treated with pesticides or herbicides can be toxic. Avoid letting your dog graze in areas that may have been treated, and prevent them from eating unknown plants.
When to call the vet
- Your dog eats grass excessively and vomits repeatedly.
- Grass eating is accompanied by lethargy, appetite loss or other signs of illness.
- You suspect your dog ingested a toxic substance.
More behaviour insights
Explore related behaviour guides:
- Why dogs eat poop – coprophagia explained.
- Why dogs chew furniture – underlying causes of destructive chewing.
- Why dogs bark – understand different types of barking and how to manage them.
Last updated: February 2026.