While owning a dog is a wonderful experience, there are times when it can be downright scary. For example, the sight of a beloved dog vomiting blood is one of the most frightening things that can happen to a dog parent.

Now, if this ever happens to your pet, you need to get them to a veterinarian immediately. Your vet is an expert, and they’ll be able to tell if the issue is serious.

But it’s also important to know why bloody vomit occurs in dogs, how to spot it, and what can be done to fix the issue.

Dog Vomiting Blood: Why Does This Happen?

Now, there are many different reasons why the vomiting of blood – also known as hematemesis – occurs. But it’s important to note that this issue isn’t as uncommon as you think. Many dogs will go through hematemesis at one time or another.1

What can you do if you think your dog is vomiting blood?

  • First, check to confirm that the blood isn’t coming from a minor cut on the dog’s mouth or on their gums. If not, try to assess how much blood is being thrown up.

  • If at all possible, try to bring a sample of the bloody vomit to your vet. This can help to get a faster diagnosis.

  • Small amounts of brightly colored blood, or blood clots, are often caused by a physical injury to the throat. If the blood is more darkly-colored or appears like coffee grounds, this is more than likely caused by an ulcer or deeper internal bleeding. Internal bleeding can be deadly if ignored.2

It’s obviously upsetting to see this happening to your pooch, but you need to get to the veterinarian as fast as you can. However, don’t automatically assume the worst. Many of the causes of this issue are serious, but some are relatively minor and can be treated effectively.

Here are some of the more common reasons why hematemesis occurs.

Ingesting a Poisonous Substance

Unfortunately, dogs tend to eat a lot of things they shouldn’t. This can sometimes lead to severe problems. One example is chocolate.

When a dog eats too much chocolate, the result can be the vomiting of blood and other problems. Some of these issues can even be fatal.3

Another example is the everyday household chemicals you take for granted. For instance, antifreeze consumption results in dog poisonings every winter. The ethylene glycol in antifreeze is so poisonous that just 2 tablespoons may kill a medium-sized dog.

Your dog may appear a little “drunk” and disoriented as an early symptom of ethylene glycol poisoning and bloody vomit can occur from internal bleeding.

A vet has several antidotes up their sleeve for this, so if you think that your pooch may
have ingested antifreeze, get them to your vet as quickly as possible.4

Eating a Foreign Object

Staying with the “getting into everything” theme, dogs will often eat all manner of things, including —

  • ToysDog Vomiting Blood | Dr Marty
  • Shoes
  • Sticks
  • Chunks of furniture
  • Q-tips
  • Bottle caps

And don’t underestimate the power of a dog bone to inflict damage, even though dogs are renowned for chewing on bones. Bones can shatter into very sharp pieces, potentially creating bleeding cuts around the mouth or puncturing the stomach or intestines.

Foreign objects have the ability to cause severe damage to the stomach and intestinal tract and may result in symptoms like diarrhea and the vomiting of blood.5

Swelling or Abnormal Tissue Growth

Swelling or the growth of abnormal tissue in certain areas of the body, like the esophagus or stomach, can lead to hematemesis.6

Stomach Ulcers

Just like a human, a dog can develop ulcers in the stomach. These painful sores on the lining of the stomach don’t heal well, as they are constantly being hit by the stomach’s acids.

Stomach ulcers can cause blood in a dog’s vomit. If your pup’s vomit looks like coffee grounds, this is often a clear sign of an ulcer or intestinal bleeding.

Certain powerful medications can also cause this problem, as can an overgrowth of harmful bacteria in the gastrointestinal tract. Stress can also play a role.7

Your vet can supply medications to help relieve this condition before it gets any worse.

Damaged Blood Vessels

Retching or throwing up food can make small blood vessels in the stomach break. When this happens, you might see a small amount of blood in your pet’s vomit that appears as bright red streaks or spots.

If you only see a fleck or two of blood, there shouldn’t be any reason to worry.8 However, you might still want to take him or her to the veterinarian in order to stay on the safe side.

Inflammatory Bowel Disease

When a dog’s bowels are inflamed, this may lead to not only an upset stomach and severe diarrhea but also hematemesis. The causes of inflammatory bowel disease aren’t known, but it is believed that immune system issues, nutrition, and genetics all play a role.9


Dog Vomiting Blood | Dr MartyIf a dog suffers some sort of internal injury, he or she could begin vomiting blood. For example, a perforated organ could result in blood accumulating in the lungs. This, in turn, can ultimately lead to hematemesis.10

And trauma to the nose or mouth can lead to a dog ingesting blood and later throwing it up.11


This is a condition that occurs due to the inability of a dog’s body to properly clot blood. It could develop for a number of reasons.

Liver failure might be to blame. Another possible reason might be a low blood platelet count due to a medication. Heat stroke, serious burns, and exposure to poison could also result in coagulopathy.12


Some parasitic worms can cause bleeding in the intestinal tract. These worms are known as hookworms, and they literally “hook” themselves to the intestines, feeding on the blood. A large number of hookworms may cause a dog to vomit blood, as well as bloody diarrhea. 13

Hookworms can be very dangerous, so visit your vet immediately if you suspect them.

Diagnosing the Problem

It may not be a pleasant thought, but paying close attention to the type of vomit that’s coming from your dog could save their life. That can give your vet a clue as to what type of issue your pup is experiencing.

For example, if there are red streaks in the vomit, that could mean the bleeding is coming from the small intestine or the stomach. If the vomit looks like coffee grounds, that likely means the blood is coming from the large intestine.14

A dog might also be showing other symptoms in addition to hematemesis, such as –

  • Diarrhea
  • Lethargy
  • Appetite loss

Dog Vomiting Blood | Dr MartyThese could be signs that the bleeding is coming from the stomach or upper area of the digestive tract.15

Once you get your dog to the veterinarian, they’ll perform several tests to determine the cause of the problem. These include analysis of fecal samples, x-rays, a blood count, organ screening, a blood-clotting profile, and possibly an ultrasound in order to get a good picture of your dog’s internal organs.16

Your dog may be given fluids in order to address any potential dehydration due to vomiting. Your veterinarian may even recommend that your pup stays at the medical facility for a few days to be thoroughly examined.

But if your dog is vomiting blood, the best thing to do is to immediately take them to your vet for an examination.

Treatment Options

Now, there are several ways that a veterinarian will treat a dog who is vomiting blood. The specific method of treatment will depend on the cause of hematemesis.

Say for instance the cause is a stomach ulcer. Your vet may simply recommend a bland diet and natural remedies. These include herbs such as slippery elm, licorice root, and alfalfa. Some veterinarians may recommend aloe vera to help reduce stomach acid and aid healing of the ulcer.17

If the dog is vomiting blood due to swallowing a foreign object, your veterinarian may choose to give your pet a laxative to help the object pass through the intestinal tract. The dog may also receive antibiotics in order to reduce the chance of an infection.18

Dog Vomiting Blood: The Bottom Line

If your dog starts to vomit blood, you have every right to be upset and worried… after all, you’re afraid for your baby.

Dog Vomiting Blood | Dr MartyHowever, the key is staying calm and getting your pet to the vet ASAP. If your vet’s office is closed, go to the nearest emergency animal clinic.

And also remember: As troubling as this situation may be, it doesn’t necessarily mean the worst will happen to your beloved companion. If you get the medical attention your dog needs as fast as possible, there is a very good chance the problem can be fixed and your pup will return to good health.

Learn More About Dog Vomiting:
My Dog is Vomiting Bile (What Should I Do?)
Is Your Dog Vomiting White Foam? Here’s a List of 7 Possible Reasons
Why is My Dog Vomiting Dark Brown?

*Article edited 4/8/2019.

12. https://www.merckvetmanual.com/dog-owners/blood-disorders-of-dogs/bleeding-disorders-of-dogs