The short answer: most dogs eat grass, and most of the time it’s completely normal, but the reasons behind it are more interesting than you might think, and there are a few situations where it’s worth paying closer attention.
Almost Every Dog Does It
If your dog eats grass, they’re in very good company. Studies show that up to 80% of dogs eat grass or other plants on a regular basis. It happens across every breed, every age, and every diet type. Small dogs do it. Large dogs do it. Puppies do it. Senior dogs do it. Dogs eating premium raw food do it, and so do dogs eating kibble.
The behaviour is so widespread that researchers consider it a normal part of being a dog, not a disorder, a deficiency, or a sign that something has gone wrong. That said, “normal” doesn’t mean “random.” Your dog likely has a reason, even if they can’t tell you what it is.
Six Reasons Your Dog Eats Grass
There’s no single explanation that covers every grass-eating dog. Most veterinarians and animal behaviourists point to a combination of the following.
1. Instinct
Dogs are omnivores, not strict carnivores. Their wild ancestors ate entire prey animals, including the stomach contents of herbivores, which were full of partially digested plant material. Eating grass may simply be a leftover instinct from thousands of years of evolution. Your dog isn’t making a conscious nutritional decision – they’re following a deep, hardwired impulse that says “eat this.”
2. They Like the Taste
Sometimes the simplest answer is the right one. Many dogs genuinely enjoy the taste and texture of fresh grass, especially young, tender shoots in spring and early summer. You might notice your dog is pickier than you’d expect. They bypass dry, brown patches and head straight for the freshest, greenest blades. That’s not a medical issue. That’s a preference.
3. Digestive Support
This is the most common theory people hear: “My dog eats grass because their stomach is upset.” There’s some truth to it, but the picture is more nuanced than that.
Some dogs do eat grass when they feel nauseous, and some dogs vomit after eating grass. Research shows that fewer than 25% of dogs vomit after eating grass, and fewer than 10% show signs of illness beforehand. So while some dogs may use grass to settle their stomach or trigger a purge, the vast majority eat it without any digestive distress at all.
If your dog occasionally eats grass and then throws up, that’s usually nothing to worry about. If it happens frequently, that’s a conversation to have with your vet.
4. Fibre and Nutritional Needs
Grass is a source of fibre, and some researchers believe dogs seek it out when their diet lacks enough roughage. One well-known case study followed a dog that ate grass daily for years. After the owner switched to a high-fibre diet, the grass-eating stopped entirely within days.
This doesn’t mean every grass-eating dog needs a diet change. But if your dog obsessively seeks out grass, it’s worth looking at their food. A high-quality diet with adequate fibre (from vegetables, pumpkin, or a well-formulated kibble) can sometimes reduce the behaviour.
5. Boredom
Dogs that spend long stretches in the yard without much to do will often turn to grass-eating as something to occupy their time. It gives them a sensory experience: the smell, the texture, the act of pulling and chewing. For an under-stimulated dog, it’s just something to do.
You’ll often notice this pattern in dogs that eat grass primarily when they’re outside alone but show little interest in it during active walks or play sessions. If boredom is the driver, more exercise, mental stimulation, and interactive play will usually reduce the behaviour on their own.
6. Anxiety or Stress
Some dogs eat grass as a coping mechanism when they feel anxious, stressed, or overstimulated. It’s similar to how some people bite their nails or fidget under pressure. The repetitive motion of pulling and chewing grass can have a self-soothing quality.
If your dog tends to eat grass more intensely during stressful situations (visitors arriving, loud noises, being left outside, changes in routine), anxiety may be playing a role. In these cases, the grass-eating is a symptom, not the problem. Addressing the underlying stress will usually resolve the behaviour.
When Grass-Eating Is Nothing to Worry About
In most cases, grass-eating is harmless. Here are the signs that your dog’s habit falls into the “totally fine” category:
- They eat grass casually and in small amounts
- They don’t vomit afterward (or only rarely)
- They’re otherwise healthy, eating normally, and maintaining their weight
- They only eat untreated grass (no pesticides, herbicides, or fertilizers)
- Their energy level and behaviour are normal
- It doesn’t seem compulsive or frantic
If all of those boxes check out, your dog is just being a dog. You can relax.
When You Should Pay Attention
While occasional grass-eating is normal, certain patterns deserve a closer look. Talk to your veterinarian if you notice any of the following:
- Sudden increase: Your dog never cared about grass before, and now they can’t stop eating it. A sudden change in behaviour always warrants attention.
- Frequent vomiting: Occasional vomiting after eating grass is one thing. Vomiting multiple times a week is another. This could point to a gastrointestinal issue that needs investigation.
- Frantic or compulsive eating: If your dog is desperately gulping down large quantities of grass (not casually nibbling), they may be trying to address nausea, acid reflux, or another digestive problem.
- Weight loss or appetite changes: If grass-eating comes alongside a decreased appetite, weight loss, diarrhea, or lethargy, there may be an underlying health issue.
- Eating other non-food items: If your dog eats grass, dirt, rocks, socks, or other non-food objects regularly, this could be pica, a condition that sometimes signals a nutritional deficiency, gastrointestinal disorder, or behavioural issue.
In any of these situations, a vet visit is the right call. It’s always better to check and find nothing than to ignore a warning sign.
How to Reduce Grass-Eating (If You’re Concerned)
If your dog’s grass-eating habit bothers you, or if you’re concerned about pesticide exposure, here are some practical steps you can take.
Review Their Diet
Make sure your dog’s food provides enough fibre and meets their nutritional needs. If you’re unsure, ask your vet about adding steamed vegetables (green beans, carrots, broccoli) or a spoonful of plain canned pumpkin to their meals. Many dogs reduce their grass intake once their diet includes more plant-based fibre.
Increase Exercise and Stimulation
A dog that gets enough physical exercise and mental stimulation is less likely to eat grass out of boredom. Longer walks, puzzle feeders, training sessions, and interactive play all give your dog’s brain and body something better to do.
Keep Your Lawn Chemical-Free
If your dog eats grass and you don’t want to stop the behaviour, make sure the grass they’re eating is safe. Avoid using pesticides, herbicides, and chemical fertilizers on areas where your dog grazes. Many lawn care products carry warnings about pet exposure for good reason.
Redirect the Behaviour
When you see your dog heading for the grass, redirect them. Your Bark Busters trainer can show you how to correct this behaviour. This works best when paired with more exercise and stimulation, so the dog has less motivation to graze in the first place.
Address Anxiety
If stress or anxiety is driving the grass-eating, the most effective approach is to work on the root cause. A professional dog trainer can help you identify what’s triggering the anxiety and teach your dog (and you) better ways to manage it.
A Quick Note About Toxic Plants
While grass itself is generally safe, not everything growing in your yard or along your walking route is harmless. Many common garden plants, flowers, and shrubs are toxic to dogs. If your dog has a habit of eating plants, make sure you know which ones in your yard and neighbourhood are dangerous.
Some of the most common toxic plants in Canadian yards and gardens include:
- Lily of the Valley
- Azaleas and Rhododendrons
- Tulip and Daffodil bulbs
- Foxglove
- Sago Palm (in warmer regions)
- Rhubarb leaves
- Yew
If you suspect your dog has eaten a toxic plant, contact your veterinarian or the ASPCA Animal Poison Control Centre (888-426-4435) immediately.
The Bottom Line
Your dog eats grass because they’re a dog. In the vast majority of cases, it’s a normal, harmless behaviour rooted in instinct, taste preference, or simple habit. Unless your dog is vomiting frequently, eating grass frantically, or showing other signs of illness, there’s usually no reason to worry.
Keep your lawn free of chemicals, make sure their diet covers all the bases, and give them plenty of exercise and mental stimulation. If the behaviour seems excessive, compulsive, or tied to anxiety, it’s worth getting a professional involved.
Sometimes the little quirks that worry us most turn out to be the most normal things our dogs do.
Need Help With Your Dog’s Behaviour?
If anxiety, boredom, or a behavioural pattern you can’t solve on your own drives your dog’s grass-eating, Bark Busters can help. Our certified trainers work with dogs in their own homes, the environment where the behaviour actually happens, using natural communication methods that build trust and lasting results.
Every Bark Busters program comes with a Written Lifetime Guarantee. You always have all the training support you need with us!
Bark Busters has certified in-home dog trainers in communities across Canada, from Hamilton to Barrie to Edmonton. Find your local trainer and give your dog the support they deserve.