When your dog is throwing up and there is blood in their stool, it’s understandable to feel alarmed.
These symptoms may seem frightening, but they’re not always an immediate emergency.
Still, they can indicate something serious going on internally that needs attention. Dog throwing up and blood in stool can result from a wide variety of conditions—some mild and self-limiting, while others can be life-threatening if not treated quickly.
We outline the common causes of dog throwing up and blood in stool, potential risks involved, and what you should do if your dog exhibits these symptoms. We’ll also look at when to seek veterinary help and how you can keep your dog safe from recurring issues.
Here’s why dog throwing up and blood in stool happens
Dog throwing up and blood in stool typically happens due to irritation, inflammation, or injury in the digestive tract. Common causes include gastrointestinal infections, ingestion of toxins or foreign objects, dietary indiscretion, parasites, or conditions like hemorrhagic gastroenteritis and ulcers.
These issues can damage the stomach or intestinal lining, leading to vomiting and bleeding.
Sometimes, a dog may vomit once and have a spot of blood in their poop, and recover quickly. But if vomiting and bloody stool continue, or if they are accompanied by other signs like lethargy, drooling, or collapse, it’s time to investigate further.
Common Causes Of Dog Throwing Up and Blood In Stool
Gastrointestinal infection
One of the most common reasons for a dog throwing up and blood in stool is a gastrointestinal infection caused by bacteria, viruses, or parasites.
Infections like parvovirus, coronavirus, and salmonella can cause both vomiting and bleeding in the digestive tract.
These pathogens irritate the lining of the stomach and intestines, resulting in inflammation, vomiting, and sometimes bloody diarrhea or stools.
Parasitic infestations such as hookworms, whipworms, and giardia can also damage the intestinal lining, leading to both symptoms.
Related: Dog is Vomiting, Has Diarrhea, and Not Eating (Here’s Why)
Ingestion of foreign or toxic substances
Dogs are curious creatures and often eat things they shouldn’t.
Ingesting sharp objects like sticks, bones, or toys can injure the gastrointestinal lining, causing internal bleeding that appears as blood in the stool, along with vomiting.
Ingesting toxic substances such as household cleaners, pesticides, or spoiled food can cause poisoning, leading to both vomiting and bloody stools.
Hemorrhagic gastroenteritis (HGE)
Hemorrhagic gastroenteritis is a condition where dogs suddenly develop vomiting and large amounts of bloody diarrhea, sometimes with jelly-like consistency.
The exact cause of HGE is unknown, but it may be related to bacteria, stress, or dietary changes.
Dogs with HGE may appear normal one moment and then suddenly become very sick, with symptoms including dog throwing up and blood in stool, lethargy, and dehydration.
Dietary indiscretion or food intolerance
Another possible cause is dietary indiscretion, where your dog eats something they shouldn’t—like garbage, rich table scraps, or non-food items.
This can upset the digestive tract and trigger vomiting and blood in the stool due to irritation or inflammation.
Sudden changes in diet or consuming food your dog is intolerant or allergic to can also cause gastrointestinal upset.
Inflammatory bowel disease (IBD)
IBD in dogs refers to chronic inflammation of the digestive tract.
It can cause a range of symptoms, including intermittent vomiting, bloody stool, weight loss, and poor appetite.
The chronic irritation damages the intestinal lining, making it bleed and impairing its ability to absorb nutrients.
Dogs with IBD often show recurring signs of dog throwing up and blood in stool.
Gastrointestinal ulcers
Just like in humans, dogs can develop ulcers in their stomach or intestines.
These open sores can bleed, which leads to blood appearing in your dog’s vomit or stool.
Ulcers are often caused by certain medications (like NSAIDs), chronic stress, or underlying disease.
Symptoms may also include a bloated abdomen, drooling, or loss of appetite.
Liver or kidney disease
Advanced liver or kidney problems can interfere with blood clotting and digestion, sometimes resulting in vomiting and gastrointestinal bleeding.
In some cases, toxins that should be filtered out by these organs may build up in the bloodstream, irritating the stomach and intestines.
This irritation can lead to a dog throwing up and blood in stool.
Tumors or cancer
Gastrointestinal tumors, both benign and malignant, may cause persistent vomiting and bloody stools in dogs.
Tumors can bleed on their own or cause a blockage that leads to vomiting and further damage to the GI tract.
Older dogs are more likely to develop such conditions.
Stress or anxiety
While it may not be the most obvious cause, extreme stress can trigger physical symptoms in dogs, including vomiting and bloody stools.
This is especially true in high-strung or nervous dogs.
Changes in environment, routine, or separation anxiety can cause stress-induced colitis, leading to the symptoms.
Blood clotting disorders
Certain conditions, including rat poison ingestion, autoimmune diseases, or genetic clotting disorders, can make your dog more prone to internal bleeding.
If your dog is throwing up and has blood in stool and also shows signs of bruising or bleeding from the gums, a clotting disorder could be the cause.
Related: Dog throwing up and drooling (Causes and when to seek help)
What to do and when to seek help
If your dog is throwing up and passing blood in their stool, it’s important not to panic—but don’t ignore it either.
Here’s what you can do:
1. Observe your dog closely
Take note of when the symptoms began, what your dog last ate, the color of the blood in the stool (bright red or dark and tarry), and how often the vomiting or diarrhea occurs.
This information will be crucial for your vet.
2. Withhold food temporarily
In mild cases, withholding food for 12–24 hours can help the stomach settle.
Ensure your dog still has access to clean water to prevent dehydration.
3. Keep them hydrated
If vomiting has stopped, offer small amounts of water or an electrolyte solution.
If your dog refuses to drink or vomits water, call your vet immediately.
4. Do not give human medications
Never administer over-the-counter human medications without veterinary approval, as many are toxic to dogs and can worsen symptoms.
5. Try a bland diet
If symptoms are improving after the fasting period, you can introduce a bland diet such as boiled chicken and rice in small portions.
Gradually transition back to their regular food over a few days if tolerated.
6. Seek veterinary help when…
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Vomiting and bloody stool persist for more than 24 hours
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You notice dark, tar-like stools (indicating digested blood)
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Your dog appears lethargic, weak, or in pain
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There’s blood in vomit or vomit resembles coffee grounds
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Your dog is a puppy, senior, or has underlying health issues
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You suspect poisoning or foreign object ingestion
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Your dog shows signs of dehydration (sunken eyes, dry gums, lethargy)
Your vet may run diagnostic tests such as bloodwork, fecal exams, x-rays, or ultrasound to determine the cause.
Depending on the diagnosis, treatment could involve fluid therapy, anti-nausea medication, antibiotics, dewormers, or even surgery.
Key Takeaway
Seeing your dog throwing up and blood in stool is unsettling, but recognizing the symptoms and understanding their possible causes can help you take timely action.
From dietary indiscretion and stress to more serious issues like infections or ulcers, there are many reasons why these symptoms may occur.
Occasional vomiting or slight blood in the stool might not require emergency care, but persistent or severe symptoms always warrant a vet visit.
Your dog’s health can decline quickly if dehydration or internal bleeding occurs, so it’s always better to err on the side of caution.
By staying observant and proactive, and seeking veterinary care when needed, you can protect your dog’s health and help them recover quickly from whatever’s causing their discomfort.