When your dog is throwing up blood and pooping black stool, it can indicate a serious problem affecting the digestive tract. You may notice bright red blood in the vomit, vomit that resembles coffee grounds, or black, sticky, tar-like poop.
Black, tar-like stool can indicate digested blood from bleeding in the stomach or upper intestines, while blood in vomit may indicate bleeding or injury in the upper digestive tract.
Both symptoms occurring together raise particular concern for significant gastrointestinal bleeding.
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Dog Throwing Up Blood and Pooping Black: Why It Happens
A dog throwing up blood and passing black stool may have bleeding somewhere in the digestive tract.
When blood enters the stomach or upper intestines, it can be partially digested, making the vomit look like coffee grounds and the stool appear black and tar-like. This black stool is called melena.
Possible causes include stomach ulcers, medication-related gastrointestinal injury, swallowed foreign objects, poisoning, blood-clotting disorders, and other serious digestive diseases.
The exact cause cannot be determined from appearance alone, but the combination needs immediate veterinary assessment because blood loss and complications can become life-threatening.
Dog Throwing Up Blood and Pooping Black: Common Causes
Stomach Ulcers
Stomach ulcers are sores in the stomach lining that can damage blood vessels and cause bleeding.
If blood is vomited or passes through the intestines, it may appear in both the vomit and stool.
Certain medications, underlying illnesses, and other digestive problems can contribute to ulcer formation.
A dog may also develop reduced appetite, abdominal discomfort, or weakness, but the absence of these additional symptoms does not rule out bleeding.
Read more: Black Dog Poop (Signs, causes and treatment)
Medication-Related Gastrointestinal Bleeding
Some medications, particularly certain anti-inflammatory drugs, can irritate the stomach lining and contribute to ulcers or gastrointestinal bleeding. The risk depends on the medication, dose, duration of use, and the dog’s health.
If your dog is taking medication, tell the veterinarian exactly what was given and when.
Do not give additional medication or change a prescribed treatment without veterinary instructions.
Related: Dog throwing up bile and blood (Possible causes)
Poisoning
Some toxins can damage the digestive tract or interfere with normal blood clotting. Anticoagulant rodenticides, for example, can cause serious internal bleeding.
If your dog may have eaten rat poison, human medication, or another toxic substance, seek emergency veterinary care immediately.
Do not wait for more symptoms to appear or attempt to induce vomiting unless a veterinarian specifically instructs you to do so.
Swallowed Foreign Objects
Dogs sometimes swallow bones, toys, fabric, or other objects that can injure the digestive tract or cause an obstruction.
Depending on the location and severity of the injury, bleeding, vomiting, abdominal pain, and changes in stool may occur.
Repeated vomiting, a painful or swollen abdomen, or suspected ingestion of an object makes the situation especially urgent.
Do not attempt to make your dog vomit or remove an object without veterinary guidance.
Blood-Clotting Disorders
Conditions that interfere with normal blood clotting can cause bleeding inside the body, including in the digestive tract.
Some toxins and underlying illnesses can also affect the body’s ability to stop bleeding.
Possible warning signs include pale gums, weakness, unusual bruising, or bleeding from other areas.
However, these signs may not all be present, so the absence of visible external bleeding does not make the symptoms safe to monitor at home.
Related: Dog pooping black poop but acting normal (Here’s why)
Other Serious Digestive Diseases
Severe gastrointestinal inflammation, certain infections, and other diseases affecting the stomach or intestines can cause bleeding and vomiting.
Some conditions can worsen quickly, especially when accompanied by dehydration or significant blood loss.
The color and appearance of the vomit and stool can help the veterinarian assess the problem, but testing and examination may be needed to identify the underlying cause.
Dog Throwing Up Blood and Pooping Black but Acting Normal
Even if your dog is eating, walking, or behaving normally, vomiting blood and passing black, tar-like stool should not be considered harmless.
Dogs can sometimes appear relatively well during the early stages of gastrointestinal bleeding.
Do not wait for your dog to become weak or lose its appetite before seeking care. Contact a veterinary clinic immediately and explain both symptoms so the team can prepare for your dog’s arrival.
Dog Throwing Up Blood and Pooping Black With Weakness
A dog throwing up blood and pooping black while experiencing weakness may have serious bleeding in the digestive tract.
Possible causes include stomach ulcers, poisoning, severe gastrointestinal inflammation, clotting disorders, or damage to the digestive tract.
Vomiting blood combined with black stool and weakness may indicate significant blood loss or another life-threatening condition.
This is a veterinary emergency. Take the dog to an emergency veterinarian immediately, as blood loss can lead to shock and become fatal without early treatment.
Do not give human medications, food, or home remedies, and do not induce vomiting.
Keep the dog calm during transport and, if possible, bring a photo or sample of the stool and details of any medications or substances it may have ingested. Do not delay seeking care to collect these items.
Related: Dog Pooping Black Bloody Mucus (What it means)
What to Do If Your Dog Is Throwing Up Blood and Pooping Black Poop
Do not attempt to treat these symptoms at home. Your dog needs emergency veterinary assessment now.
While arranging transport, take these precautions:
Contact the nearest veterinary clinic or emergency animal hospital and tell them your dog is vomiting blood and passing black stool.
Keep your dog quiet and handle them gently.
Do not force your dog to eat or drink, particularly if vomiting continues. Ask the veterinarian for instructions while you arrange immediate care.
Do not give human medicines, painkillers, antacids, or home remedies.
If poisoning is possible, bring the product packaging or a photograph of it, if safe to do so.
If practical, take photographs of the vomit and stool to show the veterinarian, but do not delay treatment to collect samples.
If your dog becomes weak or collapses, tell the clinic immediately. Veterinary guidance recommends prompt professional care for vomiting blood and other signs of a possible emergency.
When to Call or Visit the Vet
A dog throwing up blood and pooping black stool requires immediate emergency veterinary care, even if the symptoms have occurred only once, or if your dog is still walking or appears relatively alert.
Additional emergency warning signs include:
Pale or white gums.
Repeated vomiting or substantial amounts of blood.
Black, sticky, tar-like stool.
Weakness, unusual lethargy, or collapse.
A swollen or painful abdomen.
Rapid breathing or difficulty standing.
Suspected poisoning or ingestion of a foreign object.
Do not wait for all these signs to develop. The combination of bloody vomit and black stool is already serious enough to warrant immediate assessment.
Dog Throwing Up Blood and Pooping Black: Treatment
Treatment depends on the source and severity of the bleeding. The veterinarian may provide intravenous fluids, medication to manage vomiting or protect the stomach lining, and other supportive care.
Blood transfusions may be necessary if blood loss is severe. Treatment may also involve managing poisoning, ulcers, clotting disorders, or an intestinal obstruction, depending on the diagnosis.
Dogs with significant bleeding may need hospitalization and close monitoring.
Key Takeaway
A dog throwing up blood and pooping black stool may be experiencing bleeding in the digestive tract. Possible causes include stomach ulcers, medication-related injury, poisoning, foreign objects, and blood-clotting disorders.
Although the symptoms do not establish a specific diagnosis, this combination should always be treated as an emergency until a veterinarian has assessed your dog.
Do not wait for your dog to become lethargic or for the symptoms to happen again. Contact a veterinary clinic and arrange immediate care.
Early treatment is essential to identify the cause, control bleeding, and address complications such as shock or dehydration.
