If your dog is throwing up grass and bile, it’s often a sign that something isn’t quite right in their digestive system.
While an occasional episode might not be alarming, persistent vomiting of grass and yellow bile may signal an underlying issue.
We walk through the causes of your dog throwing up grass and bile, what it means, and when to seek veterinary help.
Table of Contents
Here’s Why Dog Throwing Up Grass and Bile Happens
Dog throwing up grass and bile often indicates an irritated or empty stomach. Dogs sometimes eat grass to induce vomiting or soothe gastrointestinal discomfort. When the stomach is empty, the dog may vomit bile—a yellowish fluid produced in the liver—which can irritate the stomach lining further. This combination suggests your dog may be experiencing nausea, digestive upset, acid reflux, or even an underlying condition like gastritis, intestinal blockage, or pancreatitis.
If this behavior happens occasionally, it might not be serious. However, frequent episodes of vomiting grass and bile warrant a veterinary evaluation
Why Dogs Eat Grass in the First Place
Before diving into medical causes, it’s helpful to understand why dogs eat grass. This behavior is surprisingly common and can be considered normal in moderation. Here are a few reasons your dog might be munching on greenery:
To induce vomiting: Some dogs instinctively eat grass when they’re feeling unwell to make themselves vomit.
Boredom or anxiety: Dogs left alone for long periods or those lacking stimulation might chew grass out of boredom or stress.
Nutritional deficiency: A lack of fiber or other nutrients may push dogs to seek out grass as a supplement.
They like the taste: Some dogs simply enjoy the texture or taste of grass.
While grass eating alone isn’t typically dangerous, if it leads to your dog throwing up grass and bile frequently, it’s time to look deeper.
Common Causes of Dog Throwing Up Grass and Bile
1. Empty Stomach or Hunger Pukes
One of the most common causes of a dog throwing up bile is an empty stomach.
Bile can build up in the stomach when there’s no food to digest, leading to irritation and vomiting.
Dogs often eat grass during this time to try and ease the discomfort or prompt vomiting.
Signs to look out for:
Vomiting early in the morning or late at night
Yellow or greenish vomit with visible grass
Normal behavior otherwise
If this is the case, feeding your dog smaller, more frequent meals might help reduce the episodes.
Related: Dog eating grass and not eating (Explained)
2. Gastrointestinal Irritation or Inflammation
A dog throwing up grass and bile could be dealing with mild gastritis or other forms of GI tract inflammation. Grass can irritate the stomach lining further, especially if it’s coarse or contains chemicals like pesticides.
Causes of GI irritation include:
Dietary indiscretion (eating garbage or spoiled food)
Sudden diet change
High-fat or spicy foods
Ingesting foreign objects
If your dog vomits multiple times or shows signs of discomfort, consult a vet.
3. Bilious Vomiting Syndrome (BVS)
Bilious vomiting syndrome is a condition in which a dog vomits bile, especially after long periods without food. Dogs with BVS tend to vomit early in the morning or late at night when their stomachs are empty. Eating grass may worsen the vomiting.
Symptoms include:
Intermittent vomiting of yellow bile
Often occurs on an empty stomach
Normal appetite and behavior otherwise
Feeding a small snack before bedtime and early breakfast can often resolve this issue.
4. Dietary Sensitivities or Food Intolerance
Some dogs may develop gastrointestinal upset due to food allergies or intolerances. If your dog eats grass and vomits bile after meals or snacks, the culprit might be their diet.
Watch out for:
Vomiting after meals
Diarrhea or soft stool
Excessive gas or bloating
A food trial with a vet-approved hypoallergenic diet can help identify the specific food issue.
5. Pancreatitis
Pancreatitis in dogs is a serious condition that causes inflammation of the pancreas.
It can lead to nausea, vomiting bile, abdominal pain, and inappetence. Eating grass may be a response to nausea.
Symptoms include:
Sudden vomiting (often bile)
Lethargy
Painful abdomen
Loss of appetite
Diarrhea
This condition requires immediate veterinary attention and supportive care.
Related: Dog eating grass then vomiting green stuff (Explained)
6. Parasites or Infections
Intestinal parasites, such as roundworms or giardia, can irritate a dog’s digestive tract, leading to nausea and vomiting. Dogs may try to self-medicate by eating grass. Additionally, bacterial or viral infections can lead to similar symptoms.
Key signs:
Vomiting with or without diarrhea
Weight loss
Dull coat
Worms in stool
A stool sample test can help diagnose and treat the problem quickly.
7. Toxin Ingestion
If your dog throws up grass and bile suddenly and appears lethargic or distressed, poisoning could be a cause.
Lawns treated with pesticides, herbicides, or fertilizers can be harmful if ingested.
Red flags include:
Sudden vomiting
Diarrhea or drooling
Shaking or seizures
Collapse
Seek immediate veterinary help if you suspect your dog consumed a toxic substance.
8. Liver or Kidney Disease
Chronic vomiting of bile, especially when combined with weight loss, lethargy, or behavior changes, can point to liver or kidney issues.
These organs are responsible for filtering toxins and supporting digestion.
Warning signs:
Frequent vomiting
Poor appetite
Increased thirst and urination
Pale gums or jaundice
Bad breath
Blood work and diagnostic imaging are needed to confirm these conditions.
What to Do If Your Dog Is Throwing Up Grass and Bile
Here’s a quick guide on what steps to take if your dog throws up grass and bile:
Observe your dog closely: Take note of when the vomiting happens, what the vomit looks like, and any accompanying symptoms.
Avoid further grass access: Prevent your dog from eating more grass until the vomiting stops and you’ve identified the cause.
Hydrate: Offer small amounts of water to prevent dehydration but avoid overloading their stomach.
Feed bland meals: A bland diet like boiled chicken and rice can help soothe your dog’s stomach.
Monitor their behavior: If your dog is lethargic, has diarrhea, or continues vomiting, consult your vet immediately.
When to Seek Veterinary Help
You should call your veterinarian if:
Vomiting persists more than 24 hours
There’s blood in the vomit or stool
Your dog is lethargic or refuses food
Your dog has a history of medical issues
You suspect they ingested something toxic
The sooner you get help, the better the chances of a full recovery.
Key Takeaway: Dog Throwing Up Grass and Bile
A dog throwing up grass and bile may not always indicate a serious condition, but it should never be ignored—especially if it happens frequently.
Whether due to an empty stomach, dietary indiscretion, bilious vomiting syndrome, or a more serious illness like pancreatitis or toxin ingestion, it’s important to monitor your dog’s symptoms closely.
If the vomiting of grass and bile is an isolated incident, try feeding your dog more frequent, smaller meals and limit their grass access.
However, if symptoms persist or worsen, contact your veterinarian to rule out serious causes and ensure your dog receives the care they need.
By staying attentive and proactive, you can help your dog bounce back to good health and avoid unnecessary complications.