Why Is My Dog Throwing Up Blood? What Vets Say

Discovering blood in your dog’s vomit is undoubtedly alarming. Your heart races, your mind floods with worst-case scenarios, and suddenly you’re frantically searching for answers at 2 AM. But here’s the good news: while hematemesis (the fancy veterinary term for vomiting blood) absolutely warrants professional attention, it’s not always a sign of a catastrophic emergency. Understanding what causes bloody vomit in dogs and when to panic can help you respond appropriately and get your furry friend the care they need.

As pet parents, we’ve all experienced the unpleasant surprise of discovering our dogs have been sick. But when that vomit contains blood, the stakes feel higher. The truth is, there are numerous reasons why your dog might be throwing up blood, ranging from relatively minor issues to serious medical conditions. Some causes are easy to treat, while others require immediate veterinary intervention. Let’s dive into what vets want you to know about this concerning symptom.

Common Causes of Bloody Vomit in Dogs

The causes of hematemesis in dogs are remarkably diverse. Your veterinarian will need to conduct a thorough examination to pinpoint the exact culprit. However, understanding the most common reasons can help you prepare for that vet visit with useful information about your dog’s recent behavior and health.

Gastritis and Inflammation tops the list of causes. When your dog’s stomach lining becomes inflamed—whether from eating something questionable, dietary indiscretion, or food sensitivities—it can bleed. This is often accompanied by regular vomiting, and the blood may only appear after several rounds of heaving.

Foreign Objects represent another significant concern. Dogs are notorious for swallowing things they shouldn’t. Toys, bones, string, plastic, and other objects can lacerate the stomach or intestinal lining, causing internal bleeding that manifests as bloody vomit. Puppies and certain breeds are particularly prone to this mischievous behavior.

Ulcers in the stomach or small intestine can cause bleeding. These painful sores develop from various causes, including stress, certain medications, or underlying diseases. Interestingly, yellow vomit sometimes precedes bloody vomit when ulcers are present.

Coagulation Disorders prevent blood from clotting properly. Conditions like hemophilia or thrombocytopenia (low platelet count) cause dogs to bleed internally, which appears in vomit. Rat poison ingestion is a common culprit that triggers these clotting problems.

Severe Gastroenteritis from infections (bacterial, viral, or parasitic) can damage the digestive tract enough to cause bleeding. Parvovirus, in particular, is notorious for causing bloody vomit in unvaccinated or incompletely vaccinated puppies.

Liver Disease compromises the body’s ability to produce clotting factors, leading to internal bleeding. Dogs with liver problems often show other symptoms like jaundice, lethargy, and abdominal pain.

Kidney Disease can cause uremic gastritis, where toxins in the bloodstream irritate and damage the stomach lining, resulting in bloody vomit.

Understanding the Types of Blood in Vomit

Not all blood in vomit looks the same, and the appearance can actually provide clues about the source of bleeding. Veterinarians pay close attention to these details during diagnosis.

Bright Red Blood (Hemoptysis) indicates fresh bleeding, typically from the mouth, throat, or upper digestive tract. If your dog is bleeding from their gums or has a mouth injury, you might see bright red blood in vomit before any stomach involvement occurs.

Dark Red or Maroon Blood suggests bleeding that occurred higher in the digestive system, where stomach acid has begun breaking down the blood. This “coffee ground” appearance—yes, that’s what vets actually call it—indicates the blood has been in the stomach for a bit longer.

Black or Tarry Vomit (Melena) represents digested blood that originated from the upper digestive tract. This appearance means the bleeding has been ongoing long enough for significant digestion to occur.

The color and consistency of the vomit matter to your veterinarian, so take mental notes before you arrive at the clinic. Better yet, if your dog is calm enough, snap a photo (yes, really!) to show your vet. They’ve seen far worse, and this detail helps with diagnosis.

When Is Bloody Vomit an Emergency?

Determining whether your dog needs immediate emergency care or can wait for a regular veterinary appointment is crucial. While all bloody vomit warrants professional evaluation, some situations are more urgent than others.

Seek Emergency Care Immediately If:

• Your dog is vomiting blood repeatedly and cannot keep anything down
• The vomit contains large amounts of blood (not just streaks or specks)
• Your dog is showing signs of shock: pale gums, rapid heartbeat, weakness, or collapse
• Your dog is lethargic, won’t eat, or seems in severe pain
• You know your dog ingested rat poison, medication, or a foreign object
• Your dog has pre-existing conditions like liver disease or bleeding disorders
• The bloody vomiting is accompanied by bloody diarrhea
• Your dog is very young, very old, or has a compromised immune system

Schedule a Vet Appointment Soon (Within 24 Hours) If:

• You see small amounts of blood in vomit that appears to be a one-time occurrence
• Your dog is otherwise acting relatively normal and eating
• The vomiting has stopped after one or two episodes
• Your dog has mild symptoms with no signs of shock or severe distress

When in doubt, err on the side of caution. Call your veterinarian and describe the situation. They can advise whether your dog needs to be seen immediately or if you can wait for a regular appointment. Most vets would rather have you call with “false alarms” than miss a genuine emergency.

How Vets Diagnose the Problem

Your veterinarian will use a systematic approach to determine why your dog is throwing up blood. Expect a thorough investigation that combines history, physical examination, and diagnostic tests.

Medical History is your vet’s first detective tool. Be prepared to answer detailed questions: When did the vomiting start? How many times has it happened? What does the vomit look like? Has your dog eaten anything unusual? Are there any other symptoms? Has your dog been around other sick animals? What medications and supplements does your dog take? This information helps narrow down the possibilities significantly.

Physical Examination involves checking your dog’s temperature, heart rate, and respiratory rate, plus palpating the abdomen to assess for pain or abnormalities. Your vet will also examine the mouth and throat for injuries or bleeding sources.

Blood Work reveals crucial information about your dog’s overall health. A complete blood count (CBC) checks for anemia, infection, and clotting problems. A blood chemistry panel assesses liver and kidney function. Coagulation tests evaluate your dog’s ability to clot.

Imaging Studies might include X-rays to check for foreign objects or other abnormalities. Ultrasound provides detailed views of internal organs and can reveal tumors, inflammation, or other issues. In some cases, endoscopy (using a camera to visualize the stomach interior) helps identify ulcers or other lesions.

Fecal Testing checks for parasites that might be causing gastrointestinal bleeding.

This multi-pronged diagnostic approach ensures your vet doesn’t miss anything important. It might seem extensive, but it’s the best way to identify the underlying cause and create an effective treatment plan.

Treatment Options and Next Steps

Treatment depends entirely on the underlying cause. Once your veterinarian identifies why your dog is throwing up blood, they’ll recommend an appropriate course of action.

For Gastritis and Minor Inflammation: Your vet might recommend fasting your dog for 12-24 hours, followed by a bland diet. What you can give your dog for upset stomach often includes plain boiled chicken, white rice, or prescription digestive diets. Medications like famotidine or omeprazole reduce stomach acid and promote healing.

For Foreign Objects: If your dog has swallowed something, surgery might be necessary to remove it. The sooner this happens, the better the outcome, as a perforated stomach becomes life-threatening.

For Ulcers: Treatment includes medications to reduce stomach acid and allow ulcers to heal. Your vet might also identify and address the underlying cause—whether that’s stress, medication side effects, or infection.

For Infections: Antibiotics treat bacterial infections, while supportive care (fluids, rest, bland diet) helps your dog recover from viral infections. Home remedies for dog vomiting can complement veterinary treatment but shouldn’t replace professional care for serious infections.

For Coagulation Disorders: If rat poison is the culprit, your dog needs vitamin K therapy immediately. Other bleeding disorders require specific treatments based on the underlying condition.

For Liver or Kidney Disease: These serious conditions require long-term management with prescription diets, medications, and regular monitoring. Early intervention significantly improves quality of life and longevity.

Supportive Care: Regardless of the cause, your dog might need IV fluids to correct dehydration, medications to control nausea, and close monitoring. Hospitalization might be necessary for severe cases.

Recovery timelines vary dramatically. Simple gastritis might resolve in days with proper care. Foreign object removal requires weeks of recovery. Chronic conditions like liver disease require lifelong management. Your vet will provide specific guidance based on your dog’s diagnosis.

Prevention Strategies for Your Dog

While you can’t prevent every health issue, you can reduce the risk of some common causes of bloody vomit.

Prevent Foreign Object Ingestion: Keep small objects, toys with loose parts, bones, and string out of reach. Supervise playtime, especially with puppies. Choose durable toys designed for your dog’s size and chewing strength.

Maintain a Healthy Diet: Feed high-quality dog food appropriate for your dog’s age, size, and health status. Avoid sudden diet changes, which upset the digestive system. Keep human food, especially toxic items, away from your pup.

Regular Veterinary Care: Annual wellness exams catch health problems early. Vaccinations protect against serious infectious diseases. Parasite prevention protects against internal parasites that cause gastrointestinal bleeding.

Manage Stress: Stress contributes to gastritis and ulcers. Provide a calm environment, regular exercise, and mental stimulation. If your dog has anxiety, work with your vet on management strategies.

Medication Management: Some medications increase ulcer risk. Use them only as directed, and always give them with food unless your vet specifies otherwise. Discuss potential side effects with your veterinarian.

Avoid Toxins: Keep rat poison, antifreeze, medications, and other toxins completely inaccessible. Be aware that certain human foods are toxic to dogs. If you suspect poisoning, contact ASPCA Animal Poison Control immediately.

Watch for diarrhea and other gastrointestinal issues: Early intervention prevents progression to more serious conditions. If your dog has persistent diarrhea or vomiting, see your vet promptly.

Frequently Asked Questions

Is bloody vomit always an emergency?

Not necessarily. Small amounts of blood in vomit, especially if it’s a one-time occurrence and your dog is otherwise acting normal, might warrant a regular vet appointment rather than emergency care. However, large amounts of blood, repeated vomiting, or signs of shock always require emergency evaluation. When in doubt, call your veterinarian for guidance.

Can I treat bloody vomit at home?

No. While you can provide supportive care like fasting and bland food, bloody vomit requires professional diagnosis. The underlying cause might be serious, and delaying veterinary care could allow the condition to worsen. Always seek professional evaluation.

What’s the prognosis if my dog is throwing up blood?

Prognosis depends on the underlying cause. Simple gastritis has an excellent prognosis with proper treatment. Foreign objects require surgery but generally have good outcomes if caught early. Serious conditions like liver disease or bleeding disorders require long-term management. Your veterinarian can provide a more specific prognosis once they’ve diagnosed the problem.

How long does recovery take?

Recovery timelines vary dramatically. Mild gastritis might resolve in days. Foreign object removal requires weeks of recovery. Chronic conditions require ongoing management. Your vet will provide specific expectations based on your dog’s diagnosis.

Can stress cause my dog to throw up blood?

Stress doesn’t directly cause bleeding, but it can cause gastritis, which might lead to bloody vomit if severe enough. Stress management is important for overall health and can help prevent stress-related gastrointestinal issues.

Should I be worried about my dog having hemophilia if they throw up blood once?

A single episode of bloody vomit doesn’t indicate hemophilia. While bleeding disorders are possible, they’re far less common than gastritis or other inflammation. Your vet will run appropriate tests if they suspect a clotting disorder.

What should I feed my dog after bloody vomit?

After your vet gives the all-clear, start with a bland diet of plain boiled chicken and white rice, or ask your vet about prescription digestive diets. Introduce normal food gradually over several days. Always follow your veterinarian’s specific recommendations.

Can my dog’s diet cause bloody vomit?

Yes. Food sensitivities, sudden diet changes, or eating something toxic can cause gastritis and bloody vomit. Additionally, knowing your dog’s health baseline helps you recognize when dietary issues might be involved. Always transition to new foods gradually and monitor your dog’s response.

When should I consider emergency care versus regular appointment?

Consider emergency care if your dog shows signs of shock, is vomiting large amounts of blood repeatedly, is extremely lethargic, or if you know they ingested something toxic. Otherwise, a same-day or next-day regular appointment is appropriate. Call your vet if you’re unsure.

Are certain dog breeds more prone to bloody vomit?

Some breeds are predisposed to certain conditions. For example, certain breeds have higher rates of gastric dilatation-volvulus (bloat), which can cause bloody vomit. Discuss breed-specific health concerns with your veterinarian, especially if you have a predisposed breed.