Why does my dog eat grass?
Reviewed against AKC, VCA Animal Hospitals, ASPCA and AVMA material. Last updated 5 October 2026.
Eating grass is common in dogs and on its own it is a watch-and-log sign, not an emergency. Eight red flags change that. Six mean a vet now, including retching with nothing coming up, a hard swollen belly, or grass treated with weed killer. Two mean a vet visit within 24 to 48 hours.
Below is the same urgency table the free 1-minute check uses, with the source behind each line. Nothing here is a diagnosis: the point is to tell you how fast to call, and what to say when you do.
Urgency table: grass eating
| What you see | How fast | Source |
|---|---|---|
| Nothing but grass eating: your dog is bright, eating and drinking normally | Watch and log | AKC, VCA |
| Trying to vomit but nothing comes up, or a swollen, hard belly | Vet now | VCA, bloat (GDV) |
| May have eaten a toxic plant, or grass treated with chemicals (weed killer, fertilizer, slug pellets) | Vet now | ASPCA |
| Struggling to breathe, or gums look pale, white, blue or gray | Vet now | AVMA |
| Collapsed, can't stand up, or is unusually unresponsive | Vet now | AVMA |
| Having or just had a seizure (stiff body, paddling legs, not responding) | Vet now | VCA, seizures |
| In severe pain: crying out, or can't get comfortable | Vet now | AVMA |
| Vomiting more than twice after eating grass | Vet in 24 to 48 hours | AKC |
| Eating grass frantically along with diarrhea, weight loss or not eating | Vet in 24 to 48 hours | VCA |
What each level means
- Vet now. Call your vet or the nearest emergency vet clinic now. Don't wait to see if it passes.
- Vet in 24 to 48 hours. Book a visit within 24 to 48 hours. If your dog gets worse or a red flag appears, go now.
- Watch and log. This is not an all-clear. Watch closely and log what you see. If it lasts, gets worse or any red flag appears, call your vet.
If the lawn was sprayed, or a plant was chewed
Chemicals on the grass are the part that can hurt, and they are also the part you can check. Weed killer, fertilizer and slug pellets all belong on the emergency row above. Poison lines, in the US (a consultation fee may apply):
- ASPCA Animal Poison Control: (888) 426-4435
- Pet Poison Helpline: (855) 764-7661
Take the product packaging, or a photo of the label, with you. The ASPCA keeps a searchable list of toxic and non-toxic plants, linked in the sources below.
What to write down for your vet
These four things turn "he's been eating grass" into something a vet can work with. Write them on your phone before the visit.
- How much and how often
- Vomiting afterwards?
- Was the area sprayed or treated?
- Changes in appetite or poop
A short phone video of the behaviour helps more than a description does.
Check your dog in one minute
The free check asks what you see, applies the table above plus the four signs that are an emergency on their own, and gives you an urgency level and a list to bring to the vet. No email needed.
Questions
Is eating grass an emergency?
On its own, no. It starts at watch and log. It becomes an emergency if your dog is retching with nothing coming up, has a hard swollen belly, may have eaten a toxic plant or chemically treated grass, is struggling to breathe, has pale gums, collapsed, had a seizure, or is in severe pain.
Does eating grass mean my dog has an upset stomach?
Not reliably. AKC and VCA Animal Hospitals both describe grass eating as common behaviour in dogs that are otherwise well, and most dogs that eat grass don't vomit afterwards. What matters is what comes with it: repeated vomiting, diarrhea, weight loss or loss of appetite.
What if the grass was treated with weed killer or fertilizer?
Treat it as an emergency. Call your vet, or a poison line above. A consultation fee may apply. Take the product packaging or a photo of the label with you.
Should I stop my dog eating grass?
This page doesn't diagnose and doesn't prescribe treatment, so that is a question for your vet. What you can do is record how often it happens, whether vomiting follows, and whether the lawn has been sprayed, and bring those notes to the visit.
Sources
- AKC — Why does my dog eat grass? Accessed 5 October 2026.
- VCA Animal Hospitals — Why dogs eat grass. Accessed 5 October 2026.
- VCA Animal Hospitals — Bloat: gastric dilatation and volvulus in dogs. Accessed 5 October 2026.
- ASPCA — Toxic and non-toxic plants. Accessed 5 October 2026.
- AVMA — First aid tips for pet owners. Accessed 5 October 2026.
- VCA Animal Hospitals — Seizures in dogs. Accessed 5 October 2026.
More from Guides Daily
Not veterinary advice, and not a diagnosis. In an emergency, contact your vet or an emergency animal hospital. Written and published by Guides Daily; see our editorial policy.