If your dog is eating grass and not pooping, it’s natural to be concerned.
While occasional grass eating in dogs is common and usually harmless, when this behavior is paired with a lack of bowel movements, it may be a sign of a digestive issue or a more serious underlying problem.
We outline the potential causes of a dog eating grass and not pooping, what it could mean for their health, and when you should seek veterinary help.
Dog eating grass and not pooping: why it happens
When a dog is eating grass and not pooping, it can be a sign of an underlying issue affecting their digestive system. This behavior may be triggered by constipation, gastrointestinal blockage, dietary issues, dehydration, stress and anxiety, worms or intestinal parasites, or lack of physical activity.
While grass-eating is a relatively normal behavior in dogs, pairing it with the absence of bowel movements suggests the dog may be trying to self-regulate discomfort or stimulate digestion.
Common Causes of Dog Eating Grass and Not Pooping
Constipation
One of the most common reasons a dog is eating grass and not pooping is constipation.
Grass may act as a natural fiber source, which dogs instinctively seek out when they have trouble defecating.
However, eating grass doesn’t always relieve the problem, especially if the underlying issue is more severe.
Constipation in dogs can occur due to dehydration, a lack of fiber in their diet, insufficient exercise, ingestion of bones or foreign materials, or a medical condition such as an enlarged prostate or spinal issues.
Signs of constipation to look for include:
Repeated attempts to defecate with no success
Straining while squatting
Hard or dry stool
Loss of appetite
Lethargy or discomfort
If constipation persists, a dog may continue eating grass in an attempt to stimulate digestion, often with no results.
Related: Dog eating grass and not eating (Here’s why)
Gastrointestinal blockage
Another serious cause of a dog eating grass and not pooping is a gastrointestinal obstruction.
This can happen when your dog swallows something they shouldn’t—like a toy, bone fragments, or fabric—that gets stuck in the intestines or colon.
When blockage occurs, food and waste cannot pass through the digestive tract properly.
This often leads to symptoms like:
Persistent vomiting
Bloating or abdominal pain
Complete lack of bowel movements
Whining or restlessness
If your dog is eating grass and not pooping for more than 24 hours, and especially if vomiting is also present, a gastrointestinal obstruction should be considered an emergency requiring immediate veterinary care.
Diet-related issues
Sudden dietary changes, poor-quality food, or food intolerances can also result in your dog eating grass and not pooping.
Some dogs may experience gastrointestinal discomfort from eating highly processed foods or consuming human table scraps.
In these cases, your dog may eat grass as a way to self-soothe or settle their stomach.
However, poor digestion or lack of fiber can lead to slower gut movement, making defecation difficult or absent altogether.
Switching to a high-fiber, easily digestible diet with plenty of hydration may help regulate your dog’s digestion and eliminate the need for grass consumption.
Related: Dog eating grass and not throwing up (Explained)
Dehydration
Dogs need water for their digestion to function properly.
Dehydration can lead to harder stools and slow intestinal transit time.
If your dog is not drinking enough water and is also eating grass and not pooping, constipation or impacted stool may be the reason.
Dry kibble diets with low moisture content can contribute to this issue, especially in dogs that are not naturally inclined to drink a lot of water.
To prevent this, always provide clean water and consider adding moisture to your dog’s meals through wet food, broth, or dog-safe fruits and vegetables.
Stress and anxiety
Stress can affect your dog’s digestive system. Dogs experiencing anxiety from environmental changes, new pets, loud noises, or separation from their owners may start eating grass excessively.
In some cases, this is a form of coping mechanism.
Stress can also slow down digestion, leading to symptoms like decreased appetite, delayed bowel movements, and lethargy.
If your dog is eating grass and not pooping and you’ve recently noticed changes in their routine or environment, stress might be the root cause.
Signs of stress in dogs include:
Pacing
Whining or barking
Hiding or avoiding contact
Excessive licking
Panting without physical exertion
Worms and intestinal parasites
Parasites such as roundworms or hookworms can cause gastrointestinal irritation that leads your dog to eat grass.
Infected dogs may suffer from inflammation or blockages in the intestines, resulting in disrupted bowel movements.
Though parasites often cause diarrhea, some dogs may actually struggle to pass stool if the infestation is large enough to interfere with normal gut function.
Regular deworming, especially for outdoor dogs, helps prevent this problem.
Lack of physical activity
A sedentary lifestyle can contribute to digestive issues.
Movement helps stimulate the bowels, and dogs that don’t get enough exercise may be more prone to constipation.
A dog eating grass and not pooping might simply need more walks and playtime to get things moving.
Regular physical activity supports healthy digestion and may reduce the urge to graze on grass.
What to do if your dog is eating grass and not pooping
If your dog is eating grass and not pooping, here’s what you can do:
1. Monitor your dog closely
Track your dog’s behavior, appetite, water intake, and attempt to poop.
Make note of any additional symptoms such as vomiting, lethargy, or abdominal swelling.
2. Check their hydration levels
Ensure your dog has constant access to fresh water.
You can check hydration by gently pinching the skin on the back of the neck.
If it doesn’t snap back quickly, your dog may be dehydrated.
3. Examine their diet
Reassess the quality and fiber content of your dog’s food.
Gradually switch to a high-fiber or sensitive stomach formula if necessary.
Avoid table scraps and sudden diet changes.
4. Increase physical activity
Encourage walks and active play.
Daily exercise helps move food through your dog’s system and can reduce both stress and constipation.
5. Provide natural digestive aids
Pumpkin puree (plain, not spiced), dog-safe probiotics, or a small amount of olive oil can sometimes help ease constipation naturally.
Always consult your vet before adding supplements.
6. Rule out foreign object ingestion
If your dog is showing signs of distress or you suspect they swallowed a non-food item, do not wait.
A blockage can become fatal if untreated.
7. Visit the veterinarian
If more than 24-48 hours have passed and your dog is still eating grass and not pooping, or if they display concerning symptoms like vomiting, pain, or bloating, consult your vet immediately.
X-rays or blood tests may be necessary to determine if there’s an obstruction or illness.
When to seek veterinary help
You should seek veterinary help right away if:
Your dog hasn’t pooped in over 48 hours
They are vomiting in addition to eating grass
There’s abdominal swelling or signs of pain
Your dog shows signs of dehydration
Your dog is lethargic, weak, or losing weight
You suspect they ingested a toy or foreign object
The dog is a senior, puppy, or has existing health conditions
These signs could indicate a serious medical issue like an intestinal blockage, toxin ingestion, or disease requiring professional intervention.
Key takeaway
A dog eating grass and not pooping can be a minor issue or a warning sign of something more serious.
Occasional grass consumption isn’t uncommon, but when it’s followed by no bowel movement, it’s time to investigate.
Constipation, dehydration, poor diet, stress, or gastrointestinal obstructions could all be to blame.
While some cases may resolve with dietary changes or hydration, others may require immediate veterinary care.
By staying observant, making thoughtful changes, and acting quickly when needed, you can help your dog feel better and prevent potential complications from escalating.
Always consult your vet when in doubt—your dog’s digestive health depends on it.