Why Do Dogs Eat Grass?
If you've ever watched your dog munch on grass like a little lawnmower, you might’ve wondered, Is it normal? Is it healthy? Is something wrong? You're not alone. One of the most common questions veterinarians get is: "Why does my dog eat grass?"
In this article, we’ll uncover the truth behind this curious behaviour using insights from scientific research. We’ll also explore whether eating grass is beneficial or harmful for dogs, and what dog parents should do.
Is It Normal for Dogs to Eat Grass?
Yes, eating grass is a common and generally normal behaviour in dogs. While the exact reason varies from pup to pup, experts agree that for most dogs, it’s not something to worry about.
“Vet-backed fact: Studies (Hart, BL et al 2008) show that up to 79% of dogs eat grass, and most do not show any signs of illness after doing so.”
Why Do Dogs Eat Grass? 6 Possible Reasons
1. They’re hungry, and it’s yummy!
Eating grass helps simply hungry dogs feel full, akin to our cheeky trips to the fridge for a snack while waiting for dinner. Many dogs will snack on grass every day, typically in the morning, and this is quite okay! (Bjone, SJ et al 2007)
Some dogs also enjoy the fresh, slightly sweet flavour or texture of grass, especially after rain. It’s similar to our own cravings.
2. It’s Fun and Instinctual
Dogs are natural scavengers, and there’s no complex reason, just curiosity and enjoyment. Sniffing, chewing, and exploring are all part of natural dog behaviour.
3. Dietary Fibre and Digestion
Grass offers roughage, which can help stimulate the digestive system and improve bowel movements. Some dogs may eat grass when their diet lacks fibre. Their wild ancestors ate entire animals, including the plant-filled stomachs of herbivores. Grass has always been on the menu!
4. Boredom or Attention-Seeking
If your dog is bored, under-stimulated, or left alone in the yard, grass chewing may be a way to pass the time or get your attention.
5. Upset Stomach
A common myth, busted by McKenzie (2010), is that dogs eat grass to make themselves vomit, or to self-medicate. However, less than 25% of dogs vomit after eating grass, and less than 10% show signs of being unwell beforehand, according to VCA.
Interestingly, there are some specific types of grass growing in Europe that researchers have investigated to see if dogs really do use them to induce vomiting.
6. Nutritional Deficiency
Though less common, your dog could be trying to supplement missing nutrients. If your dog’s diet isn’t balanced, they might turn to grass instinctively.
Is Eating Grass Safe for Dogs?
It’s usually safe when:
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The grass is untreated and free from chemicals
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Your dog is otherwise healthy and not vomiting
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Grazing is occasional through the day, not obsessive
In these cases, grass eating can be harmless and may even support digestion by providing roughage.
When You Should Worry
🚩 Your Dog Vomits Frequently After Eating Grass
This could signal other underlying gastrointestinal issues such as oesophagitis, Inflammatory bowel disease, or pancreatitis.
🚩 Exposure to Lawn Chemicals
Grass treated with fertilisers, weed killers, or pesticides can be dangerous. Avoid areas treated with chemicals or sprinkled with blood and bone meal.
🚩 Parasites or Contaminants
Outdoor grass may carry bacteria or parasites from other animals. Try to limit access to backyard poultry runs, and ensure your dog is on a parasite prevention program.
🚩 Compulsive Grazing
If your dog seems obsessed with eating grass, or does it every day, this may be a sign of anxiety, boredom, or a behavioural issue.
What Dog Owners Should Do
✅ Let Them Graze Safely
If your dog occasionally nibbles clean, untreated grass and shows no signs of illness, it’s usually fine.
✅ Review Their Diet
Make sure your pup’s food is nutritionally complete and balanced. Ask your vet about adding fibre or adjusting their meals, if needed.
Tips: Petzyo is formulated with whole foods like broccoli, sweet potatoes, and green peas to give your dog the pawsome fibre they need to support their gut health.
✅ Offer Enrichment
Provide interactive toys, puzzle feeders, training games, or more frequent walks to prevent boredom-related grazing.
✅ Consult Your Vet
If your dog is constantly eating grass, has other symptoms of being unwell, such as vomiting, a poor appetite, lethargy, diarrhea, or seems uncomfortable, schedule a veterinary check-up.
Common Questions About Grass-Eating Dogs
Is eating grass bad for dogs?
Not inherently. As long as the grass is clean and your dog isn’t vomiting or showing other symptoms, it’s usually safe.
Can eating grass make dogs sick?
It can if the grass is treated with chemicals or contains parasites or harmful bacteria.
Do dogs eat grass when they’re sick?
Sometimes. But in most cases, dogs eat grass without any signs of being ill beforehand.
Final Thoughts: Should You Be Worried?
For most dogs, eating grass is a normal and harmless behaviour. It could be due to hunger, curiosity, taste, digestion, or simply boredom. As long as they’re grazing in safe areas and not showing signs of illness, it’s generally nothing to worry about.
However, if your dog is vomiting frequently, seems unwell, or is obsessively chewing on grass, it’s time to consult your veterinarian.
References:
- Hart, BL. et al. Why do dogs and cats eat plants? Veterinary Medicine. 2008:648-649.
- Bjone, SJ. et al. Grass eating patterns in the domestic dog, Canis familiaris. Recent advances in animal nutrition in Australia. 2007 Volume 16. https://www.une.edu.au/staff-profiles/ers/wbrown/files/bjone-brown-price-grass-eating20patterns-raan-2007.pdf
- https://www.thekennelclub.org.uk/health-and-dog-care/health/health-and-care/a-z-of-health-and-care-issues/why-does-my-dog-eat-grass/
- https://vcahospitals.com/know-your-pet/why-do-dogs-eat-grass
- McKenzie, SJ. et al. Reduction in grass eating behaviours in the domestic dog, Canis familiaris, in response to a mild gastrointestinal disturbance, Applied Animal Behaviour Science. 2010 Volume 123, Issues 1–2, https://doi.org/10.1016/j.applanim.2009.12.003.
