Get

In Your Inbox

Dogster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Why is My Dog Throwing Up Black or Dark Red Vomit? Our Vet Explains Causes & Treatment

dog in a blanket is panting

We’re sorry to hear your dog is unwell, so we’ll get right to the point. Dark red or black vomit is usually due to blood in the vomit. Vivid red excretions usually signal fresh blood. As the blood oxidizes over time, it gets darker and turns black. Black or brown blood in the vomit is often described as having a “coffee grounds” appearance as the blood forms clumps when it coagulates.

However, before you panic, it might be a good idea to put on a rubber glove and examine the vomit. Sometimes, when your dog eats something black, brown, or red, for example, plastic, charcoal, crayons, or fertilizer, it can lead to these colors coming up in the vomit. Before rushing off to the vet, look around and see if there’s anything your cheeky little friend might have gotten into. Sometimes, these items are toxic, so a trip to the vet may still be warranted.

If you’re unsure, take a photo (we love photos) or put the vomit in a bag and take it to the vet. You should also make sure your dog is vomiting. While this sounds silly, coughing can look a lot like vomiting, and sometimes people find diarrhea and think that it’s vomit.

Dogster divider_v1_NEW_MAY_24_

What Causes Blood in Vomit?

Blood in the vomit is known as “hematemesis.” It usually signals a problem in the stomach, but there are a few other options to consider. Blood clotting disorders, for example, can lead to bleeding anywhere in the body, including the digestive tract.

Rat bait is a common toxin that prevents dogs from forming normal blood clots 48–72 hours after ingestion. If your dog has been hit by a car or some other trauma, internal bleeding could lead to blood in the vomit.

Gastric ulcers are the most common cause of blood in vomit. The stomach normally has a protective lining to guard from damage by stomach acid. The production of gastric acid and protective mucus occurs in a delicate balance, which can be disrupted, leading to gastric ulcers. Blood flow into the stomach is also an important protective feature that helps clear gastric acid from the cells and supports the turnover of cells at the surface, so any disruption to blood flow from stress, shock, or vigorous exercise can compromise the stomach’s protection.

Once a gastric ulcer forms, a vicious cycle begins because the stomach acid disrupts healing and causes more damage around the ulcer. When an ulcer affects all the layers of the stomach, the full-thickness perforation leads to stomach contents leaking into the abdomen. This is the most severe and life-threatening consequence of an ulcer.

nurse veterinarian caring a old dog at animal hospital
Image Credit: ARVD73, Shutterstock

Non-steroidal anti-inflammatories (NSAIDs) are medications that can reduce the stomach’s protective lining as a side effect. Combining NSAIDs or using NSAIDs with corticosteroids increases the risk of stomach ulcers when using these drugs. Liver failure from various causes can cause gastric ulceration.

While the mechanism for this is unknown, it may be secondary to increased gastric acid secretion or reduced blood flow to the stomach. Stomach cancers can bleed, leading to hematemesis, but they can also cause gastric ulcers by producing hormones that trigger gastric acid secretion.

Acute hemorrhagic diarrhea syndrome is a condition that is common in young, small-breed dogs, especially Miniature Schnauzers, Maltese, and Miniature Poodles. It is thought to be a sensitivity to bacterial toxins and can lead to blood in the vomit and stools.

Other possible conditions may lead to blood in the vomit:
  • Addison’s disease
  • Intestinal foreign body
  • Previous stomach surgery
  • Infections, e.g., parasitic, viral, bacterial
  • Kidney failure
  • Toxins
  • Inflammatory bowel disease
  • Pancreatitis

Seek veterinary advice if you’re concerned about your pet’s well-being.

If you need to speak with a vet but can't get to one, head over to PangoVet. It's an online service where you can talk to a vet online and get the personalized advice you need for your pet — all at an affordable price!

PangoVet_Mention-in-Content Savings V1

Dogster divider_v2_NEW_MAY_24_

How Is Blood in Vomit Treated?

veterinarian examines a dog in veterinary clinic
Image Credit: Maria Sbytova, Shutterstock

If your dog is vomiting blood, they will need urgent veterinary attention. This is not something you want to leave until next week to see it improve since even mild cases can become life-threatening quickly. In addition, if there is a significant amount of blood or your pup shows signs like lethargy, pale gums, black, tarry stools, or fresh blood in diarrhea, you should go to the emergency clinic immediately.

After taking a thorough history and examining your dog, your vet will know the likely differentials for your pet.

They will probably order some diagnostic tests, which could include:
  • Hematology: This is a complete red and white cell count to rule out anemia and low platelet counts. High white cell counts could also indicate an infection.
  • Clotting tests: Activated clotting time (ACT), prothrombin time (PT), and activated partial thromboplastin time (PTT) can ensure your dog can form blood clots.
  • Biochemistry: This looks for underlying metabolic disease and tests the organ function.
  • Imaging: This includes ultrasounds and X-rays to check for masses, intestinal foreign bodies, perforation, and other issues.
  • Gastroduodenoscopy: This involves using a scope to diagnose the cause of bleeding or evaluate surgical options.
  • Fecal testing: This identifies infectious agents like parasites, bacteria, and viruses.

Medical treatment will likely commence around the same time as the diagnostic procedures. In mild cases, vets may opt for a treatment trial instead of an extensive work-up, especially if the underlying cause is suspected based on a dog’s history.

Their treatment plan might include:
  • Bland diet
  • Gastroprotectant medications to reduce stomach acidity or provide a protective lining to the stomach
  • Anti-nausea medication
  • Treating the underlying cause, for example, stopping NSAID medication or supplementing vitamin K in cases of rat bait toxicity
  • Antibiotics if there is a bacterial infection or risk of secondary bacterial infection
  • Intravenous fluid therapy or fluid drip for dehydrated pets
  • Blood transfusion for anemic dogs

In some cases, surgery is necessary to remove tumors, correct gastric perforation, or remove ulcers that don’t respond to medical treatment. Some pups may be well enough to go home the same day as their vet visit.

In most cases, hospitalized dogs are discharged within a few days of treatment. However, some severe cases have a poor prognosis and may not recover, but it depends on your dog’s diagnosis. This is something you should discuss with your veterinarian.

Husky dog lying on vet table with doctor and master near by
Image Credit: Pressmaster, Shutterstock

Dogster divider_v1_NEW_MAY_24_

Final Thoughts

If your dog’s vomit is dark red or black, and nothing obvious that they have eaten that would lend this color, it’s likely from blood in the digestive tract. Don’t let the condition worsen before seeking veterinary help for your dog. If you’re unsure about the contents, bring a sample or some photos to help your vet get a good picture of what is happening.


Featured Image Credit: felixmontana88, Shutterstock

Want content like this delivered to you?

Sign Up For Our Newsletter

News, insights, expert advice, and everything dog

* By submitting, you agree to our Terms & Conditions and Privacy & Cookies Policy.

How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Dogster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.

Talk With A Vet Online

Peace of mind,
anywhere, anytime

Affordable vet advice

Pembroke Welsh Corgi Dog Breed: Info, Pictures, Traits & More

If you’ve been searching for a smaller dog to add to your family, you might want to consider the Pembroke Welsh Corgi. Often...

How to Certify an Emotional Support Dog: 4 Steps to Take (Vet-Reviewed)

Our canine companions improve our lives in a myriad of ways. However, dogs can improve things immensely for those dealing with emotional or...

Are Pit Bulls More Aggressive Than Other Dog Breeds? Facts & FAQ

Pit Bull aggression is an age-old topic that is divisive and often causes disputes between the two sides. Because of negative media coverage...

Why Do Dogs Bark At Fireworks? 6 Reasons & How to Help (Vet Reviewed)

Many dog owners dread certain holidays throughout the year because of the use of fireworks during those times. Independence Day, Labor Day, and...

More related

13 Heartbreaking Australian Puppy Mill Statistics to Know in 2025

Note: This article’s statistics come from third-party sources and do not represent the opinions of this website. Unfortunately, unscrupulous manufacturers and sellers have...

Can Dogs Get Drunk? Vet-Verified Facts & Risks

Dogs don’t naturally have a taste for alcohol, but some sweet alcoholic drinks or those made with milk or cream can be particularly...

Why Do Huskies Scream? 4 Main Reasons & How to Prevent it

Huskies are a very vocal dog breed, using various tones and sounds to convey their feelings. The Husky scream is one of the...

How Much Does Dog Cataract Surgery Cost? 2025 Price Guide

If your pet is blessed with a long life, the chances are high that they’ll eventually develop cataracts. These white fibrous specks in...

Keep reading

10 Best Dog Travel Bowls in 2025  – Reviews & Top Picks

Dogs often make some of the best travel companions. With so many dog-friendly places to visit, you can plan all kinds of trips with your dog. When traveling with your dog, it’s important to pack several essential supplies to make...

Border collie puppy drinking water from bowl in a park

Mossy Oak Nature’s Menu Dog Food Review 2025: Recalls, Pros & Cons

Review Summary Made in the USA and sold at Dollar General, Mossy Oak Nature’s Menu features two premium dry food recipes and three wet food formulas. Their dry food recipes are above average quality for cheaper food, but they’re not...

Dogster_Mossy Oak Nature’s Menu Dog Food Review

Can Dogs Eat Gravy? Vet-Reviewed Facts & Alternatives

Gravy can seem like a treat that many dogs can enjoy. Gravies are often meat-based, and many dogs lap them up enthusiastically. However, it’s generally not recommended for dogs to eat gravy because it can contain harmful ingredients, and it...

Can Dogs Eat Gravy

Can Dogs Eat Elderberries? Vet-Verified Facts & FAQ

The use of elderberries in human remedies has been on the rise over the past few years. You’ll find elderberry cough syrup on drug store shelves and elderberry jams and jellies floating around the grocery aisles. Not to mention, elderberry...

Can Dogs Eat_elderberries

Authority Dog Food Review 2025: Pros, Cons, Recalls & FAQ

Review Summary If you have a dog, you’re probably constantly searching for foods that will provide your pup with the nutrients that they need for proper development. Since there are various brands on the market, deciding on a particular one...

Dogster_Authority Dog Food Review

What Vegetables Can Dogs Eat? 14 Vet-Approved Healthy Options

As dog owners, we have our dog’s best interests at heart and want to keep them safe. One of the biggest risks to their health is what they put into their bodies because some foods are dangerous for dogs and...

Head portrait of a golden retriever dog eating pumpkin slice

Nulo Dog Food Review: Recalls, Pros & Cons

Review Summary Nulo was created with quality care for dogs in mind. Its founder realized that there weren’t enough care options available for dogs for last-minute requests. He also noticed that there was a bit of a health crisis in...

Dogster_Nulo Dog Food Review

Can Dogs Eat Turnips? Vet-Reviewed Facts & Safety Guide

Turnips are hardy root vegetables similar to parsnips and potatoes. Dogs can eat turnips in moderation; they can provide some health benefits and dietary fiber, and they are fine for your dog as long as it doesn’t suffer from thyroid...

Can Dogs Eat_Turnips