Why Do Dogs Eat Grass?
Last reviewed October 2026 · Based on 2 published veterinary sources (listed below)
Most dogs eat grass at some point, and in healthy dogs it's usually normal behaviour. Studies of pet dogs found most grass-eaters weren't sick beforehand and only a minority vomited afterward. Still, a sudden change — frantic grass eating, repeated vomiting — can point to stomach upset.
Likely reasons
- Instinct inherited from wild ancestors
- Boredom or wanting something to chew
- They like the taste or texture of fresh grass
- Mild stomach upset (less common than people think)
See a vet if
- Your dog suddenly eats grass frantically
- Vomiting is repeated or contains blood
- They are also not eating, lethargic or have diarrhea
- Belly looks swollen or painful
Keeping it safe
- Avoid lawns treated with pesticides or fertilizer
- Keep up with deworming — grass can carry parasite eggs
- Offer chew toys and more exercise if it's boredom
This guide is general information, not a diagnosis. If you're worried about your pet, call your vet or an emergency clinic.