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Seeing your dog throwing up blood can be frightening. Whether it’s bright red or dark brown, blood in dog vomit is always a sign that something’s wrong. Veterinarians refer to this condition as hematemesis, and according to the Journal of Veterinary Internal Medicine (JVIM), it’s often linked to gastrointestinal (GI) problems, internal injuries, or systemic illness.
Understanding what causes this symptom — and acting quickly — can save your dog’s life. This article breaks down the major causes, diagnostic steps, and treatments based on current veterinary research.
Dog Throwing Up Blood: What It Means and Why It Happens
When your dog vomits blood, it usually means there’s irritation or injury somewhere in the digestive tract — from the mouth and esophagus down to the stomach or intestines. The blood may appear as bright red streaks (fresh bleeding) or as dark brown, coffee-ground-like vomit (digested blood).
If your dog is throwing up blood or has bloody vomit, it could signal gastrointestinal bleeding or an internal injury—always treat it as an emergency and contact your veterinarian immediately.
Main Causes of Dog Throwing Up Blood
One of the most common causes of blood in dog vomit is irritation of the stomach lining. Conditions such as a dog stomach ulcer or gastrointestinal bleeding in dogs can trigger this.
Sometimes, a dog vomiting blood and bile may also indicate internal bleeding in dogs, especially if the vomit appears dark or coffee-colored.
1. Gastrointestinal Ulcers and Stomach Irritation
Gastrointestinal bleeding in dogs often starts with ulcers in the stomach or upper intestines. Ulcers can develop from:
- Long-term use of NSAIDs or steroids
- Chronic vomiting or inflammation
- Bacterial infection (Helicobacter)
Studies published in Veterinary Therapeutics Journal show that acid-reducing medications such as omeprazole and famotidine help heal ulcers faster. If untreated, ulcers can lead to severe internal bleeding in dogs, making urgent veterinary attention essential.
2. Foreign Object Ingestion
Dogs love to chew and sometimes swallow items they shouldn’t — like toys, bones, sticks, or grass. Sharp objects can scrape or puncture the stomach lining, leading to blood in vomit.
If you notice your dogs throwing up blood after eating grass, it may just be irritation. But continuous vomiting, weakness, or a bloated abdomen suggest a blockage or tear, which is a medical emergency.
Veterinarians use X-rays or ultrasounds to locate and safely remove the object before more damage occurs.
3. Poisoning and Toxic Exposure
Rodenticides (rat poison), household chemicals, and certain human medications can cause internal bleeding in dogs. According to the Pet Poison Helpline, toxins like anticoagulant rodenticides interfere with blood clotting, which can cause vomiting blood within 24–48 hours.
Other symptoms include:
- Pale gums
- Nosebleeds
- Weakness or collapse
Emergency treatment includes vitamin K therapy, IV fluids, and sometimes blood transfusions.
4. Inflammatory Bowel Disease (IBD)
Chronic inflammation of the digestive tract can damage the lining, leading to dog vomiting blood and bile. Research in the Journal of Small Animal Practice shows that diet changes, probiotics, and anti-inflammatory medications can help control IBD and prevent flare-ups.
5. Severe Infections or Parasites
Parasites such as hookworms and whipworms attach to the intestinal walls and suck blood, while bacterial infections like Helicobacter pylori can erode the stomach lining.
These conditions can cause mild but repeated bleeding, especially in puppies or dogs with weak immune systems. Deworming, antibiotics, and a high-quality diet can restore gut health and stop the bleeding.
6. Clotting Disorders or Internal Injuries
Dogs with bleeding disorders (like hemophilia) or those exposed to toxins may lose the ability to form proper clots. Even small injuries in the digestive tract can cause visible blood.
Blunt trauma, ruptured tumors, or splenic injuries can also lead to internal bleeding in dogs. Signs include weakness, pale gums, swollen abdomen, and vomiting blood. Immediate emergency treatment is crucial.
How Vets Diagnose Blood in Dog Vomit
When your dog is throwing up blood or showing signs of vomiting blood, your veterinarian will run diagnostic tests to determine the cause. These tests can reveal issues such as dog stomach ulcers, intestinal parasites, or other forms of gastrointestinal bleeding in dogs.
- Blood tests — to identify infection, anemia, or organ dysfunction.
- X-rays / Ultrasound — to detect ulcers, blockages, or tumors.
- Endoscopy — a camera helps inspect and sometimes treat stomach bleeding.
- Fecal tests — to check for parasites or bacteria.
Early diagnosis helps pinpoint the exact cause and prevents recurrence.
Treatment Options for a Dog Vomiting Blood
Treatment for a dog vomiting blood depends on the underlying cause. If internal bleeding in dogs or a dog stomach ulcer is found, your vet may recommend medication, IV fluids, or even surgery.
1. IV Fluids & Electrolytes
Rehydrates your dog and stabilizes blood circulation, especially if vomiting is continuous.
2. Acid Reducers & Protective Drugs
Medications like omeprazole, sucralfate, or famotidine protect the stomach lining and reduce acid production.
3. Antibiotics / Dewormers
Prescribed when infections or parasites are confirmed.
4. Surgery
Used to remove foreign bodies or repair intestinal damage.
5. Blood Transfusions
For dogs suffering significant blood loss or anemia.
6. Dietary Management
Switching to a bland or hydrolyzed-protein diet helps calm the stomach and prevents further irritation.
According to the Veterinary Emergency and Critical Care Journal, dogs treated early for GI bleeding have an 80–90 % recovery rate.
How to Prevent Blood in Dog Vomit
To prevent your dog from throwing up blood after eating grass or due to toxins, keep harmful substances out of reach and avoid giving human medications without veterinary advice.
- Avoiding human painkillers unless prescribed by a vet.
- Keeping poisons, bones, and sharp objects out of reach.
- Using monthly parasite prevention.
- Feeding balanced, vet-approved food.
- Scheduling annual veterinary checkups.
Preventive care is your best defense against stomach ulcers and internal bleeding.
Final Thoughts
When your dog is throwing up blood, it’s not something to wait on or “see if it stops.” Blood in vomit always means the stomach or intestines are under stress.
Veterinary research shows that dogs treated promptly for gastrointestinal bleeding recover faster and live longer. Trust your instincts, act quickly, and contact your veterinarian immediately. With professional care and supportive treatment, most dogs return to their healthy, happy selves.
Frequently Asked Questions (FAQs)
1. What should I do first if my dog throws up blood?
Stay calm, collect a small sample of the vomit (if possible), and contact your vet immediately. Avoid giving food, water, or home remedies until your vet advises — this prevents worsening irritation.
2. Can a dog vomit blood from eating grass?
Yes, but it’s usually mild. Eating rough or long grass can scratch the throat or stomach, causing small streaks of blood. If vomiting continues or your dog shows pain, see a vet to rule out internal injury.
3. How serious is gastrointestinal bleeding in dogs?
It can range from mild irritation to life-threatening bleeding. According to the American Veterinary Medical Association (AVMA), any amount of blood in vomit should be treated as an emergency until proven otherwise.
4. Can stress cause a dog to vomit blood?
Severe stress can trigger stomach acid overproduction, leading to gastritis or ulcers, which may cause minor bleeding. Chronic stress-related vomiting should always be evaluated by a veterinarian.
5. What color of blood in vomit is most concerning?
Bright red blood means fresh bleeding (often from the stomach or esophagus), while dark brown or “coffee ground” vomit indicates digested blood — both require immediate veterinary care.
6. How can I tell if my dog’s vomiting blood is an emergency?
If your dog also shows weakness, pale gums, rapid breathing, abdominal pain, or continuous vomiting, treat it as an emergency. Contact your nearest 24-hour vet clinic right away.
Conclusion: What to Do If Your Dog Is Throwing Up Blood
If your dog is throwing up blood, never ignore it. Even a small amount of blood in dog vomit can indicate gastrointestinal bleeding, a dog stomach ulcer, or other serious health conditions. Early diagnosis and treatment are critical for saving your pet’s life. Contact your veterinarian immediately for proper testing, including blood work or imaging, to determine why your dog is throwing up blood.
Avoid home remedies or waiting for symptoms to pass—dogs with internal bleeding or ongoing vomiting blood and bile can deteriorate quickly. By acting fast and following your vet’s guidance, you give your furry friend the best chance at recovery and long-term health. Remember: when your dog is throwing up blood, prompt veterinary care can make all the difference.
References
- Washabau, R. J., & Day, M. J. (2020). Canine and Feline Gastroenterology. Elsevier.
- Hall, E. J., & German, A. J. (2019). Gastrointestinal disease in small animals. Journal of Small Animal Practice.
- Willard, M. D., & Twedt, D. C. (2021). Clinical diagnosis of gastrointestinal bleeding in dogs and cats. Veterinary Clinics of North America: Small Animal Practice.
- Pet Poison Helpline. (2023). “Anticoagulant Rodenticide Poisoning in Dogs.”
- Veterinary Emergency and Critical Care Journal. (2022). “Prognosis for Dogs with Acute GI Hemorrhage.”
- American Veterinary Medical Association (AVMA). (2023). “What to Do if Your Pet Vomits Blood.”