If you’ve ever caught your dog munching on grass during a walk or playtime at the park, you’re not alone. Grass-eating is a common canine behavior, but it often leaves pet parents puzzled. Is it instinct? A health issue? Or just curiosity?
While the exact reason isn’t fully understood, research and observations provide several possible explanations. Let’s dive into the theories, myths, and safety concerns around dogs eating grass.
Why Do Dogs Eat Grass?
Instinctive Behavior
Some scientists believe grass-eating is an inherited behavior from wolves and wild canids. Studies of wolf stomach contents show plant material makes up 2–10% of what they eat. In nature, this may have been part of their balanced diet.
Supplementing a Missing Nutrient
There are cases where dogs with low-fiber diets eat plants or grass and then stop once switched to a high-fiber food. This suggests some dogs may seek grass to supplement dietary needs—especially fiber.
Normal Dog Behavior
Research indicates grass-eating is common and often unrelated to illness. Dogs tend to eat more grass before meals and less after eating, suggesting it may be linked to hunger or routine rather than health issues.
Soothing an Upset Stomach
Although many believe dogs eat grass to make themselves vomit, studies show that most dogs do not vomit after eating grass. In fact, dogs with diarrhea were observed to eat less grass, suggesting it’s not necessarily tied to stomach upset.
Curiosity and Play
Like children who try eating dirt, dogs—especially puppies—explore with their mouths. Some simply enjoy the texture or taste of grass.
Attention-Seeking
Dogs may learn that grass-eating grabs their owner’s attention. If pulling them away or offering treats follows, the behavior may become reinforced.
Can Dogs Digest Grass?
Not really. While dogs can digest some carbohydrates thanks to evolving alongside humans, grass mostly passes through their system undigested. That’s why large amounts can sometimes cause stomach irritation or blockages.
Is Eating Grass Safe for Dogs?
Grass itself isn’t usually harmful, but the real risks come from what might be on it:
Pesticides
Grass treated with chemicals like insecticides or herbicides can poison dogs. Signs include vomiting, diarrhea, excessive drooling, and decreased appetite. Seek immediate vet care if you suspect exposure.
Fecal Material
Grass can carry parasites, bacteria, or viruses from animal droppings. This includes parvovirus and intestinal worms that can make dogs very sick.
Intestinal Blockage
If a dog swallows a large amount, grass can clump and cause obstruction, especially if mixed with non-food items.
What To Do If Your Dog Eats Grass
- Ensure your dog eats a complete, AAFCO-approved diet for their life stage.
- Stop the behavior when you notice it and redirect with toys or treats.
- Keep dogs on a leash in grassy areas, especially after chemical treatments.
- If your dog has signs of illness, or if they ate recently treated grass, see your vet immediately.
How To Stop Grass-Eating Habits
- Feed before walks: A full stomach may reduce grazing.
- Time outings: Dogs tend to eat less grass later in the day.
- Redirect with training: Use positive reinforcement to encourage alternate behaviors.
- Grow safe grass: Provide untreated grass at home so your dog can satisfy curiosity without risks.
Dogs eating grass is usually normal behavior, not a sign of illness. Still, it’s important to watch for hazards like pesticides, parasites, or excessive consumption. If you’re concerned, consult your veterinarian to rule out underlying issues and keep your pup safe and healthy.
