Seeing your dog being sick and eating grass can leave you wondering whether the grass is causing the vomiting or whether your dog is eating it because they already feel unwell.
While some dogs eat grass occasionally without becoming sick, repeated vomiting together with unusual grass-eating deserves closer attention.
Looking at the timing of the grass eating, vomiting, appetite, energy, and other digestive changes can help put the behavior into context.
We explain what it may mean when a dog is sick and eating grass, what you can do at home, and when the symptoms warrant veterinary care.
Table of Contents
Dog Being Sick and Eating Grass: Why It Happens
A dog being sick and eating grass may have dietary indiscretion, gastritis, acid reflux, bilious vomiting syndrome, inflammatory bowel disease, intestinal parasites, pancreatitis, or another digestive disorder.
Some dogs eat grass once, vomit, and quickly return to normal, while others continue vomiting, develop diarrhea, lose their appetite, or become lethargic.
Monitoring the pattern of this behavior can help determine whether veterinary care is needed.
A dog may also experience:
- Vomiting bile or foam
Loss of appetite
Diarrhea
Lip licking or excessive swallowing
Lethargy
Abdominal discomfort
Dog Being Sick and Eating Grass: Common Causes
Mild Stomach Upset
A temporary stomach upset caused by eating something unusual is one of the most common reasons dogs eat grass before vomiting.
Many dogs recover after a single episode and return to normal within a day. However, repeated vomiting should be evaluated by a veterinarian.
Related: Dog eating grass and not eating (Why it happens)
Gastritis
Gastritis is inflammation of the stomach lining caused by dietary indiscretion, infections, medications, toxins, or sudden diet changes.
Dogs with gastritis often feel nauseous and may eat grass before vomiting. They may also have reduced appetite, abdominal discomfort, or diarrhea.
Bilious Vomiting Syndrome
Dogs with bilious vomiting syndrome often vomit yellow bile after their stomach has been empty for several hours, particularly early in the morning.
Some dogs begin eating grass before vomiting because they feel nauseated. Feeding a small meal before bedtime may help reduce episodes in some cases.
Acid Reflux
Acid reflux can cause irritation of the esophagus and stomach, leading to nausea, lip licking, swallowing, grass eating, and vomiting.
Symptoms may be worse after long periods without food or after certain meals. Veterinary treatment can often improve comfort.
Inflammatory Bowel Disease (IBD)
Inflammatory bowel disease causes chronic inflammation within the digestive tract, leading to recurring nausea, vomiting, and changes in appetite.
Many dogs also develop intermittent diarrhea, weight loss, and poor body condition. Long-term dietary management and medication are often required.
Intestinal Parasites
Parasites such as Giardia, whipworms, hookworms, and roundworms can irritate the digestive tract and cause nausea, vomiting, and grass eating.
Additional signs may include diarrhea, weight loss, bloating, or poor coat quality. A fecal examination is needed to confirm the diagnosis.
Related: Dog eating grass excessively (Here’s why)
Pancreatitis
Pancreatitis causes inflammation of the pancreas and commonly leads to persistent nausea and vomiting.
Dogs may eat grass because they feel nauseated, although the grass does not treat the underlying condition.
Affected dogs often become lethargic, refuse food, and develop abdominal pain. Moderate to severe cases usually require hospitalization.
Dietary Indiscretion
Eating spoiled food, garbage, rich treats, or unfamiliar foods can upset the stomach and trigger both grass eating and vomiting.
If your dog continues vomiting after eating grass or develops additional symptoms, veterinary evaluation is recommended.
Read more: Dog Being Sick after Eating Chocolate (Is it an emergency?)
Dog Being Sick and Eating Grass: What to Do
If your dog eats grass, vomits once, and quickly returns to normal, monitor them closely over the next 24 hours. Make sure fresh water is always available and observe whether the vomiting recurs.
Try to prevent excessive grass eating until you know why your dog is doing it, especially if lawns may have been treated with fertilizers, herbicides, or pesticides that could be harmful if ingested.
Keep a record of when your dog eats grass, whether vomiting occurs before or after eating it, and whether other symptoms such as diarrhea, loss of appetite, or lethargy develop.
This information can help your veterinarian identify the underlying cause.
Do not give human anti-nausea medications or allow your dog to eat chemically treated grass.
When to Call or Visit the Vet
Occasional grass eating with a single episode of vomiting may not always be serious, but recurring episodes should be evaluated.
Schedule an appointment if you notice:
Frequent grass eating followed by vomiting
Vomiting lasting more than 24 hours
Reduced appetite
Mild diarrhea
Weight loss
Mild lethargy
Recurrent nausea
Vomiting yellow bile regularly
Seek emergency veterinary attention immediately if your dog develops:
Repeated vomiting with inability to keep water down
Blood in the vomit
Severe abdominal pain
Collapse or extreme weakness
Signs of dehydration
Suspected poisoning from treated grass or plants
Suspected intestinal obstruction
Pale gums or difficulty breathing
Dog Being Sick and Eating Grass: Treatment
Veterinary treatment for a dog that is sick and eating grass begins with an examination to determine whether the vomiting is an isolated digestive problem or part of a more serious condition.
Depending on the examination, the veterinarian may recommend blood tests, fecal testing, or abdominal imaging.
Treatment may include anti-nausea medication, fluids, gastrointestinal medications, pain relief, or a prescription diet.
If testing identifies a condition requiring specific treatment, such as an obstruction or another significant gastrointestinal problem, additional medical or surgical treatment may be necessary.
Recovery and Monitoring
Recovery depends on the underlying cause. Mild stomach irritation often resolves within a day or two, while inflammatory bowel disease, pancreatitis, or chronic digestive disorders may require long-term management.
Monitor your dog’s appetite, water intake, energy level, bowel movements, and whether grass eating and vomiting become less frequent after treatment begins. Administer all medications exactly as prescribed and attend follow-up appointments if recommended.
Contact your veterinarian if vomiting becomes more frequent, blood appears in the vomit, your dog refuses food, develops diarrhea, becomes increasingly lethargic, or continues eating grass excessively despite treatment.
Key Takeaway
A dog being sick and eating grass commonly results from mild stomach upset, gastritis, bilious vomiting syndrome, acid reflux, inflammatory bowel disease, intestinal parasites, pancreatitis, or dietary indiscretion.
While many dogs occasionally eat grass without any problems, repeated grass eating accompanied by vomiting usually indicates nausea rather than being the actual cause of the vomiting.
Early veterinary evaluation can identify the underlying problem and help prevent dehydration or more serious complications.
If your dog develops repeated vomiting, blood in the vomit, severe abdominal pain, collapse, inability to keep water down, or signs of dehydration, seek emergency veterinary care immediately.