Why Do Dogs Eat Grass? (And No, They Aren’t Always Sick)
Why your dog thinks the park is an all-you-can-eat buffet.
It’s a fresh morning in London. You’ve finally found a patch of grass that isn’t covered in litter, and instead of chasing the ball, your dog is grazing like a confused sheep.
The immediate thought is: “Oh great, he’s going to be sick on the rug.” But while many owners believe dogs eat grass to self-medicate, the science tells a different story.
1. The “Vomit Theory” is Mostly a Myth
Contrary to popular belief, most dogs aren’t actually sick before they start munching on the lawn.
The Data: Studies show that less than 25% of dogs vomit after eating grass, and only about 10% show signs of illness beforehand.1
The Reality: While long blades of grass can tickle the throat and cause a gag reflex, most dogs eat it simply because they want to, not because they’re trying to induce a “system reboot”.
2. They Need the Roughage (Fibre)
Dogs are scavengers by nature, and like us, they need fibre to keep things moving.
Digestive Aid: Grass is a natural source of insoluble fibre (roughage), which helps support digestion and stool formation.
Nutritional Gap: If your dog is a habitual grazer, it might be a sign their diet is lacking in fibre or specific nutrients.
3. Boredom and Psychological “Tics”
If you’re standing in a park checking your emails while the dog has nothing to do, he might start eating grass just to pass the time.
Attention Seeking: Some dogs learn that eating grass is a great way to get their owner to stop looking at their phone and start looking at them.
The Comfort Factor: Similar to humans biting their nails, some anxious dogs graze as a self-soothing mechanism.
4. They Simply Like the Taste
Sometimes the answer isn’t deep—it’s just delicious.
Seasonal Snacking: Many dogs prefer fresh, vibrant spring grass because it’s tender and sweet.
Instinct: Wild canids have been observed eating grass for centuries; it’s a normal, instinctive behavior that predates luxury kibble.
FAQ
Is it dangerous for my dog to eat grass?
The grass itself is usually fine, but the chemicals on it aren’t. In London, be wary of pesticides, herbicides, and “slug slime” which can carry lungworm.
When should I call the vet?
If the grazing is followed by repeated vomiting, lethargy, or a sudden loss of appetite, it’s time to book an appointment.
How can I stop the grazing?
Try introducing more fibre-rich foods or a high-fibre kibble. More importantly, keep them mentally stimulated during walks with toys or training so the grass isn’t the only entertainment.
If your dog thinks he’s an herbivore, you aren’t alone. Subscribe for more guides on surviving the urban dog life.