Blood in Dog Vomit: Why Is There Blood in My Dog’s Puke?

Vomiting is a natural mechanism of your dog’s body purging things the stomach is not happy with. It is, however, not normal for it to contain blood.

With most dogs, their stomachs get plenty of reasons to complain. In general, when my dog throws up once, I don’t panic. However, regardless of the cause, profuse or persistent vomiting—with or without blood—is a problem in itself. It leads to fluid and electrolyte loss, which can impair circulation, organ function, and overall homeostasis—the system that keeps the body from “going up in flames.”

Further reading: Severe Vomiting in Dogs: What Happens in a Dog’s Body with Severe Vomiting?

The urgency of the situation increases sharply when you find blood in your dog’s vomit.

Finding blood in your dog’s vomit

Blood belongs in blood vessels, nowhere else.

When people think of blood in vomit, they usually picture bright red blood—specks, streaks, or clots mixed into what the dog brings up.

This is what it looks like when your dog is bleeding in the upper gastrointestinal tract, typically the esophagus or mouth—and sometimes the nose or lungs if they swallowed it.

Partially digested blood, such as bleeding from the stomach or further down the gastrointestinal tract, doesn’t look like blood at all—it is often brown or black. Your dog’s vomit would then look like it had coffee grounds in it. While that might look much less impressive, it is the more concerning scenario of the two.

Fresh versus digested blood

The appearance of the vomited blood depends on where it came from and how long it remained in the GI system.

Like fresh blood in the stool, it can result from direct damage to the lining tissues, whether from irritation, inflammation, or injury. In addition, profuse vomiting itself can do enough damage to cause bleeding.

Some direct reasons for fresh blood in vomit include:

• trauma
• ulcers
• foreign objects
• severe inflammation

Beyond local injury, anything that interferes with blood clotting or the body’s ability to keep blood contained within blood vessels can also result in bleeding. Further, any severe vomiting can cause enough damage to the tissues to cause bleeding.

Other potential causes include:

• gastrointestinal disease
• metabolic disorders
• infections
• liver failure
• kidney disease
• parasites
• toxins or poisons
• cancer or tumors
• clotting disorders
• inflammatory or autoimmune diseases

Don’t forget that for any blood you do see, there may be additional bleeding you don’t see.

Blood in vomit—whether fresh or digested—is reason to seek veterinary care promptly, even if no other symptoms are obvious at the time.

If your dog vomiting blood isn’t an emergency, what is?

How much blood is too much?

Any amount of visible internal bleeding is a potential emergency. Even small amounts can indicate a serious underlying problem. This is not your dog cutting a paw while running through brambles.

Other symptoms

If your dog is vomiting blood, they may also show the following signs:

• loss of appetite
• pain
• weakness
• lethargy
• and changes in the stool

What can be behind bloody vomit? Anything from:

• GI disease
• foreign bodies
• trauma, infections
• parasites
• poisons
• tumors
• ulcers
• clotting disorders
• inflammatory and autoimmune diseases
• metabolic disorders
• liver failure …

Are there any breeds that are at increased risk?

Small breeds like Miniature Schnauzers, Yorkshire Terriers, and Miniature Poodles are more prone to acute hemorrhagic diarrhea syndrome (AHDS), which can cause bloody vomit—monitor closely if your dog fits this profile.

Further reading: Update on Acute Hemorrhagic Diarrhea Syndrome in Dogs

Medications and supplements

Certain medications, including NSAIDs, and some supplements can irritate the gastrointestinal tract or interfere with normal clotting. Iron supplements are a notable example. In dogs, ingestion of iron—often from human multivitamins or prenatal vitamins—can cause severe gastrointestinal irritation and bleeding, sometimes within hours and at relatively low doses.

Be cautious about what you give your dog, and always consult your veterinarian before using medications or supplements, including products intended for people. More details are covered in the Coffee Grounds in a Dog’s Vomit article.

Source: Supplements’ toxicity risks not easy to determine as new, reformulated products hit shelves

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Dog vomit infographic

What does the color and content in your dog’s puke tell you?

Related articles:
My Dog’s Vomiting: Why Is My Dog Throwing up?
Bloody Vomit in a Dog: Susie’s Severe Stomach Upset
Bloody Diarrhea in Dogs: Duke’s Bloody Vomiting and Diarrhea
Severe Vomiting in Dogs: What Happens in a Dog’s Body with Severe Vomiting?

Further reading:
Vomiting of Blood in Dogs (Hematemesis)