Why Is My Dog Throwing Up Blood?

Sandra C. Mitchell, DVM, DABVP
By Sandra C. Mitchell, DVM, DABVP on Mar. 31, 2023
sad brown dog looking up


You hear your dog vomiting again, and at first you think they just got into the trash. But when you clean up the mess, you see that there’s blood in the vomit and you immediately start to panic.

This is a normal reaction, and yes, you should call your veterinarian right away, even if your dog appears to feel fine.

Dog Vomiting Blood: What It Looks Like

Vomiting blood is known by veterinarians as hematemesis (hema means “blood” and emesis means “vomit”). The appearance and color of the blood in the vomit is very important. In addition to making note of what came up, you should also take a few photos and bag up a sample of the vomit, both of which could be very helpful to your veterinarian.

Bright red blood that is liquid often comes from the esophagus—the tube that connects the mouth and stomach. Sometimes, if the mouth is bleeding heavily, that blood might be swallowed and then vomited back up.

Dark red blood that either is clotted or looks like coffee grounds usually indicates that it has been partially digested by stomach acid, so it likely came from either the stomach or the upper part of the intestinal tract.

When the vomit is foamy and pink-tinged or has small specks of blood, it’s usually a sign of irritation and in most cases is less serious than the other scenarios.

Coughing up Blood vs. Throwing up Blood

Coughing up blood usually means that the bleeding is located within the respiratory tract, whereas vomiting up blood indicates that the bleeding is in the GI tract. Distinguishing the difference is very important, and it’s something that your veterinarian will need to do. If you can take a video of your dog “in action” as they bring up the blood, this will be very helpful to your veterinarian.

A dog that’s vomiting will have abdominal heaving—strong motions from the abdomen that occur before the vomit is expelled from the mouth.

This differs from a coughing dog, that will likely stretch their neck forward and cough—often with a sound much like a goose’s “honk.” The bloody material may come up during the cough, after the cough, or even be swallowed again. Many dogs will end a bout of coughing with a gag that looks much like a vomit, because they will cough something up.

What To Do if Your Dog Is Throwing up Blood

For the most part, a dog vomiting blood is considered an emergency and should be seen by a veterinarian immediately. When in doubt, get it checked out. What is a minor problem now could become a very serious or even deadly one in 12 hours. The safe rule is to have any animal vomiting blood examined as soon as possible.

Other signs to watch for include:

  • Bloody diarrhea: Can indicate that the problem involves both the upper and lower gastrointestinal tract

  • Black, tarry stools: Blood is possibly being swallowed and digested

  • Pale gums: May indicate severe internal bleeding or shock

  • Weakness and lethargy

All of these signs indicate that you have an emergency on your hands.

If your dog is vomiting blood, pick up both their food and water until your pup can be seen by a veterinarian. Don’t administer anything by mouth, as it is important to determine the cause before anything is given orally.

Take some photos of the vomit, collect it in a plastic bag, take a photo of your dog’s food brand/bag, and head immediately to the closest emergency facility available to you.

If you have heard that you should give bread to a dog that’s vomiting blood, don’t do it! This is not helpful, and it can significantly complicate diagnostic testing that might be required.

Why Dogs Vomit Blood

There are quite a few reasons dogs may vomit blood, and determining the cause can go a long way to finding the cure. Some of the more common reasons include:

  • Untreated prolonged or severe vomiting of any cause: Over time, vomiting exposes the esophagus to stomach acids, which can be very irritating and lead to bleeding.

  • Intestinal parasites, especially in puppies or dogs that are not on a regular deworming schedule: Giardia is a parasite that can commonly lead to bloody vomiting as well as diarrhea.

  • Viral and bacterial infections: Viral infections such as parvovirus can be particularly dangerous to young dogs and those that are not well-vaccinated.

  • Eating a foreign body (such as socks, toys, or rocks): A foreign body stuck in the stomach or intestines is a very common and serious cause of bloody vomit.

  • Eating sharp objects: Sharp objects like bones and sticks can cause a significant amount of damage to the upper GI tract, leading to bleeding.

  • Hemorrhagic gastroenteritis (HGE): This can result in sudden, severe, bloody diarrhea and/or vomiting, quickly leading to dehydration.

  • Stomach ulcers: Though not common in dogs, these can also cause bloody vomit.

  • Inflammatory bowel disease (IBD): This can occasionally result in bloody vomit.

  • Poisons and toxins: These are a major concern, especially those that lead to problems with blood clotting, such as rat poisons.

  • Trauma: Trauma can result in both bloody vomit and bloody diarrhea.

  • Cancer: Cancer can occasionally cause bloody vomit.

How Do Vets Diagnose the Cause When Dogs Vomit Blood?

The first priority for a veterinarian will be to examine your dog and make them comfortable and stable. The vet will likely ask you a lot of questions about diet, medical history, and daily routines.

After the initial assessment, they will likely recommend diagnostic testing. Depending on the situation, this may include:

  • A fecal test to look for parasites

  • A basic blood panel to check organ function

  • Blood-clotting tests to make sure a bleeding disorder isn’t contributing to the problem

  • X-rays to look for any signs of a foreign body

  • Infectious disease testing

Depending on what’s found, additional tests may be recommended—for example, a dog with a suspected foreign body may require either endoscopy or surgery.

Treatment for Dogs Throwing up Blood

Dogs with less severe symptoms may be treated and released immediately from the veterinary hospital, but others with more severe or ongoing signs may be hospitalized for additional testing or treatment.

Each case is unique, and the treatment differs depending upon the underlying cause. For example:

  • A dog vomiting blood because of parasites will be given medication to get rid of the parasites, in addition to care for treating the symptoms.

  • In most cases, a dog that has a foreign body lodged in their intestinal tract will need surgery.

  • Viral infections are likely to need hospitalization and intensive supportive care.

However, most dogs vomiting blood, regardless of cause, will benefit from symptomatic care. This will often include:

  • Injections of fluids to treat dehydration and electrolyte imbalances (oral fluids are not recommended for dogs that are vomiting)

  • Antacids to reduce stomach inflammation

  • Anti-nausea injections to help stop the vomiting

  • Protectants to line the stomach and help bandage irritated areas

  • A bland diet to make it easy to eat once your dog is back on their feet

As scary as it is to have your dog vomiting blood, when the cause is diagnosed and treated quickly, pets do fully recover in most cases. So when in doubt, get your dog checked out!

Featured image: iStock.com/123ducu

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Sandra C. Mitchell, DVM, DABVP


Sandra C. Mitchell, DVM, DABVP


Sandra Mitchell is a 1995 graduate of the New York State College of Veterinary Medicine. Since graduation, she has worked in many fields...

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