Coffee Grounds in a Dog’s Vomit: What Is That Dark Grit in My Dog’s Vomit?

When you hear blood in vomit, you probably imagine bright red streaks. But blood doesn’t always look like that. With exposure to stomach acid, it turns dark, grainy, and clumpy—in your dog’s vomit, it will look exactly like used coffee grounds.

Coffee Grounds in a Dog's Vomit: Learn what finding coffee grounds in your dog's vomit means and when to see a vet

Could it be actual coffee grounds?

Couldn’t a dog get into the garbage and eat some actual coffee grounds?

Everything is possible, particularly with dogs—they can get into anything. If that were the case, you should be able to find evidence of that quite easily—spilled coffee grounds, a torn garbage bag, or chewed-up coffee pod.

However, if that’s what happened, you’re not in the clear, especially with a higher amount. Coffee grounds contain a high concentration of caffeine that is toxic to dogs. Caffeine toxicity generally ranges from moderate to severe.

The symptoms of caffeine toxicity can include the following:
  • vomiting
  • diarrhea
  • restlessness, pacing
  • hyperactivity
  • elevated heart rate
  • tremors
  • high blood pressure
  • seizures, collapse, or death in severe cases

The urgency and actions you need to take depend on how much grounds your dog ingested and how they’re feeling.

Coffee grounds that are NOT from coffee

Coffee Grounds in a Dog's Vomit is an emergency

If your dog’s vomit looks like coffee grounds—but they didn’t get into any—you’re almost certainly looking at digested blood that clots, oxidizes, and darkens in the stomach.

Vomit containing “coffee grounds” might come with black tarry stools. This, too, can be caused by a stomach ulcer or by ingested blood from elsewhere, such as swallowed blood from the respiratory tract. If that doesn’t have emergency written all over it, I don’t know what does.

Accompanying symptoms may include:

  • lethargy or weakness
  • dehydration
  • loss of appetite
  • pale gums
  • abdominal pain

Note: coffee-grounds vomit often has a distinct, unpleasant smell—typically foul, acidic, or metallic due to the combination of blood, stomach acids, and oxidation. It was one of the first things our veterinarian asked me when I had my own scare with Jasmine’s suspiciously-looking puke.

What causes coffee-grounds vomit in dogs?

The most common potential cause is damage in the GI tract—ulceration or erosion. It can happen as a result of the following:

  • gastritis (inflammation)
  • severe vomiting that damages the stomach lining
  • swallowed foreign body
  • stomach or intestinal mass
  • pancreatitis
  • liver disease
  • Addison’s disease
  • trauma
  • NSAIDs (Rimadyl, Metacam, aspirin, etc.)
  • corticosteroids
  • mast cell tumors (even those on the skin—because they release histamine, which increases stomach acid)

Less likely causes are lung disorders (where blood is swallowed and then vomited) or bleeding disorders. In such cases, you’d likely see many other red flags along with vomiting coffee grounds.

Does any of these sound to you like not being an emergency?

If your dog vomits what looks like coffee grounds, seek veterinary help immediately. Internal bleeding can escalate fast, and the underlying problem is often severe or life-threatening.

Hopefully, if the coffee-grounds vomit doesn’t scream emergency to you, your very ill dog will. And, hopefully, you pick up on warning signs BEFORE it gets that far.

Be especially alert when your dog is taking NSAIDs or steroid medication. These medications can damage the stomach lining and dramatically increase the risk of stomach ulcers, upper GI bleeding, and perforations.

NSAIDs (non-steroidal anti-inflammatory drugs)

While NSAIDs reduce inflammation, they also reduce the dog’s natural protective mechanisms in the stomach, making it more vulnerable to damage from stomach acid. In case you’re not familiar, common NSAIDs used for dogs include:

  • carprofen (Rimadyl®)
  • meloxicam (Metacam®)
  • deracoxib (Deramaxx®)
  • firocoxib (Previcox®)
  • grapiprant (Galliprant® — still requires caution)

Steroids

Corticosteroids such as prednisone or dexamethasone can also weaken the stomach lining and delay healing.

Combining the two is the most dangerous. That’s why your veterinarian would never prescribe both at the same time. Further, when switching, your dog needs to undergo a “washout” period.

The same risks apply to mixing the above prescription medication with OTC medications such as Pepto-Bismol. Always make your veterinarian aware of what you have given your dog—better yet, don’t give anything without your veterinarian’s approval.

Are there any breeds that are at increased risk?

Recent updates confirm breed-specific risks for acute hemorrhagic diarrhea syndrome (AHDS), a cause of GI bleeding, is higher in small breeds such as:

  • Miniature Schnauzers
  • Yorkshire Terriers
  • Miniature Poodles

Further reading: Update on Acute Hemorrhagic Diarrhea Syndrome in Dogs

Dog vomit infographic

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

Dog vomit color and content infographic

Related articles:
My Dog’s Vomiting: Why Is My Dog Throwing up?
Blood in the Vomit

Have you experienced this with your dog? Share your dog’s story.

Share you dog's story

2025 Update

Recent reports highlight GI bleeding risks from iron supplements in dogs (e.g., from human multivitamins or prenatals), where toxicity over 20 mg/kg elemental iron can cause bloody stool and severe GI upset within hours.

Be careful about what you give your dog, and always consult your veterinarian about products and dosages.

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

Categories: Blood in vomit • Coffee grounds vomit • Symptoms • Vomiting

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Jana Rade edited by Dr. Joanna Paul BSc BVSc

I am a graphic designer, dog health advocate, writer, and author. Jasmine, the Rottweiler of my life, was the largest female from her litter. We thought we were getting a healthy dog. Getting a puppy from a backyard breeder was our first mistake. Countless veterinary visits without a diagnosis or useful treatment later, I realized that I had to take Jasmine's health care in my own hands. I learned the hard way that merely seeing a vet is not always enough. There is more to finding a good vet than finding the closest clinic down the street. And, sadly, there is more to advocating for your dog's health than visiting a veterinarian. It should be enough, but it often is not. With Jasmine, it took five years to get a diagnosis. Unfortunately, other problems had snowballed for that in the meantime. Jasmine's health challenges became a crash course in understanding dog health issues and how to go about getting a proper diagnosis and treatment. I had to learn, and I had to learn fast. Helping others through my challenges and experience has become my mission and Jasmine's legacy. I now try to help people how to recognize and understand signs of illness in their dogs, how to work with their veterinarian, and when to seek a second opinion. My goal is to save others the steep curve of having to learn things the hard way as I did. That is the mission behind my blog and behind my writing. That is why I wrote Symptoms to Watch for in Your Dog, which has turned out being an award-winning guide to dog owners. What I'm trying to share encompasses 20 years of experience. Dr. Joanna Paul BSc BVSc is our wonderful sponsor and has been kind to edit and fact-check my important articles.

5 Comments
  1. Terri 22/10 – 12:22 pm

    Gosh, anything that looked like coffee grounds in my dog’s vomit would send me racing to the vet. This is terrific article on what coffee ground in your dog’s vomit could be and what to do if you see it. I’m sharing this article with all my dog parents.

    Reply
  2. DashKitten 22/10 – 10:33 pm

    Good grief this sounds scary whichever way you look at it. I would not have thought if it as dried blood but your explanation makes total sense – and its scary and YES I would be at the vet right now!

    Reply
  3. Beth 22/10 – 10:13 pm

    This is good information to know! We learned this from our pediatrician when one of our kids was sick.

    Reply
  4. Dorothy "FiveSibesMom" 22/10 – 8:15 pm

    Always excellent and important information. I was so fortunate in that none of my Huskies ever had this in their vomit, nor did they ever get into my coffee grinds. But this is something to be very concerned with and most definitely an emergency requiring a call to the vet. I’m sharing this so others can be informed as well.

    Reply

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