If your dog is throwing up grass and blood, it’s a troubling sight that no pet parent wants to witness. The presence of blood in dog vomit can indicate anything from minor gastrointestinal irritation to life-threatening conditions.
Coupled with vomiting grass, this behavior signals that your dog’s digestive system is in distress — and they may be trying to self-medicate by eating grass.
We outline the causes of a dog throwing up grass and blood, what it means, when to worry, and how you can help your furry friend.
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Here’s Why Dog Throwing Up Grass and Blood Happens
If your dog is throwing up grass and blood, it’s a sign that something is irritating their stomach or gastrointestinal tract. Dogs often eat grass when they feel nauseous or have an upset stomach, and vomiting blood—whether fresh (bright red) or digested (dark, coffee ground-like)—can indicate anything from inflammation (gastritis) to ulcers, ingestion of toxins, foreign objects, or even more serious conditions like pancreatitis or internal injury.
The combination of grass and blood suggests that the dog is trying to soothe an already irritated stomach, but the situation has escalated. This is not a symptom to ignore—vomiting grass and blood is a red flag that your dog needs prompt veterinary attention
Common Causes of Dog Throwing Up Grass and Blood
1. Gastrointestinal Irritation or Ulcers
One of the most common causes of a dog vomiting grass and blood is irritation of the stomach lining or ulcers.
Ulcers can result from:
Excess stomach acid
Non-steroidal anti-inflammatory drugs (NSAIDs)
Infections
Prolonged vomiting or stress
If the stomach lining is inflamed or ulcerated, blood can be present in the vomit.
A dog might eat grass in an attempt to soothe the irritation or to trigger vomiting to relieve discomfort.
Symptoms to watch for include:
Black, tarry stools (indicating digested blood)
Lethargy
Loss of appetite
Pale gums
If you see these signs along with blood and grass in vomit, consult a vet immediately.
Related: Dog eating grass and not eating (Explained)
2. Dietary Indiscretion
Dogs are notorious for eating things they shouldn’t — spoiled food, garbage, foreign objects, or toxic plants. Known as dietary indiscretion, this can result in an upset stomach, vomiting, and internal irritation.
The grass might be eaten as a self-soothing mechanism, but the presence of blood points to damage to the GI tract.
Common signs include:
Vomiting shortly after eating
Diarrhea
Dehydration
Lack of interest in food
In this case, the dog throwing up grass and blood may simply be reacting to something they shouldn’t have eaten — but the blood should not be ignored.
3. Ingestion of Toxins or Poisonous Substances
Toxins are a medical emergency. If your dog throws up grass and blood after being outside or around cleaning products, plants, or rodenticides, suspect poisoning.
Toxic ingestion can cause:
Vomiting (with blood)
Seizures
Lethargy or collapse
Drooling
Pale or bluish gums
Even small amounts of toxins can be fatal.
If you suspect your dog has consumed something toxic and is vomiting blood and grass, contact your vet or a poison control hotline right away.
4. Foreign Objects and Obstructions
Sometimes a dog swallows objects that become stuck in their gastrointestinal tract, causing trauma or blockage.
Vomiting blood and grass may be your dog’s way of trying to clear the obstruction.
Signs of a foreign body include:
Repeated vomiting
Abdominal pain
Inability to defecate
Whining or restlessness
Lack of appetite
If your dog is vomiting blood and grass and showing these symptoms, an X-ray or ultrasound may be necessary to locate the blockage.
Related: Dog eating grass and not bile (Explained)
5. Parasitic Infections
Intestinal parasites such as hookworms or whipworms can damage the lining of the intestines and stomach, leading to bloody vomit.
Dogs with parasites often:
Vomit (sometimes with blood)
Have diarrhea
Lose weight despite eating
Appear weak or anemic
A dog throwing up blood and grass may have worms, especially if they haven’t been dewormed recently.
A fecal exam can confirm this.
6. Kennel Cough or Respiratory Issues
While not directly related to digestion, some upper respiratory conditions like kennel cough can cause a dog to cough so violently that they end up vomiting foam, grass, and even blood due to throat irritation.
If your dog has a persistent cough along with blood-tinged vomit, see a vet to rule out infections or respiratory disease.
7. Cancer or Tumors
Though less common, tumors in the gastrointestinal tract can cause a dog to vomit grass and blood.
These tumors may bleed, causing visible blood in vomit, especially after eating or exercise.
Signs that may point toward cancer include:
Chronic vomiting
Bloody vomit or stool
Sudden weight loss
Loss of appetite
In older dogs, this possibility becomes more likely.
Diagnostic imaging and blood work are needed to confirm the diagnosis.
Color and Type of Blood in Vomit: What to Look For
When your dog is throwing up blood and grass, noting the color of the blood can give clues about where the problem lies:
Bright red blood: Likely from the mouth, throat, or upper stomach (fresh bleeding).
Dark brown or coffee-ground appearance: Indicates digested blood, often from ulcers or deeper GI bleeding.
Both scenarios are serious and warrant veterinary care.
What to Do if Your Dog Is Throwing Up Grass and Blood
If your dog vomits grass and blood, stay calm but act promptly.
Here are steps to take:
Remove food and water for 6–12 hours to allow the stomach to rest (unless your vet advises otherwise).
Monitor your dog closely for signs like weakness, additional vomiting, diarrhea, pale gums, or collapse.
Collect a sample of the vomit if possible to show your vet — it helps with diagnosis.
Call your veterinarian immediately if the vomiting continues or if your dog shows any signs of distress.
This is especially crucial if your dog is a puppy, senior, or has existing health conditions, as they are more vulnerable to dehydration and complications.
When to Seek Emergency Help
You should seek urgent veterinary care if your dog shows:
Repeated vomiting (more than once or twice in a short period)
Bright red or dark blood in vomit
Signs of pain or distress (whining, restlessness, bloating)
Pale gums or rapid breathing
Diarrhea along with vomiting
Lethargy or collapse
Vomiting grass and blood is never “normal” and should not be ignored.
Prevention Tips
While you can’t prevent every cause of vomiting grass and blood in dogs, some steps can reduce the risk:
Keep toxins and garbage out of reach
Supervise your dog outdoors to prevent ingestion of harmful substances
Feed a consistent, high-quality diet
Avoid sudden diet changes
Stay on top of deworming and parasite prevention
Schedule regular vet checkups
Key Takeaway: Dog Throwing Up Grass and Blood
A dog throwing up grass and blood may be trying to soothe an irritated stomach, but the presence of blood signals a deeper issue.
From ulcers and infections to poisoning and foreign body ingestion, many causes of bloody vomit in dogs are serious and require prompt veterinary care.
Always take this combination of symptoms seriously. Early intervention can make a big difference in your dog’s recovery and long-term health.
If in doubt, call your vet — it’s always better to be safe than sorry when your best friend is hurting.