Coffee Grounds in a Dog’s Vomit: What Is That Dark Grit in My Dog’s Vomit?
When talking about blood in vomit, I touched on the fact that blood doesn’t always look like blood, meaning doesn’t always have the typical bright red appearance. Fresh blood does; blood that has already been digested does not. So instead, in the vomit, it looks like coffee grounds.

I include an illustration because I don’t want to freak anybody out with graphic images. But if you want to see what that really looks like, there is an example photo here.
Could it be actual coffee grounds?
Couldn’t a dog get into the garbage and eat some coffee grounds?
Well, everything is possible, particularly with dogs. If that were the case, you should be able to find evidence of that quite easily. However, if that’s what happened, you’re not in the clear. You might be looking at potential caffeine poisoning. Caffeine toxicity generally ranges from moderate to severe.
The symptoms of caffeine toxicity can include the following:
- vomiting
- diarrhea
- hyperactivity
- restlessness
- high blood pressure
- abnormal heart rate, tremors … and, in severe cases,
- seizures, collapse, and death.
The urgency and actions you need to take depend on how much was ingested and how your dog is feeling.
Coffee grounds that are not from coffee
What appears like coffee grounds might not be coffee grounds at all but digested blood.
Vomit containing “coffee grounds” be accompanied by black tarry stools. This, too, can be caused by a stomach ulcer, or it can be digested blood that comes from elsewhere, such as swallowed blood from the respiratory tract.
Your dog will likely refuse their food, be lethargic, and have diarrhea.
What can cause this?
The most common potential cause is damage in the GI tract; ulceration, or erosion. It can happen as a result of the following:
- gastritis
- trauma
- severe vomiting
- foreign body
- mass/tumor
- liver disease
- pancreatitis
- Addison’s disease
- drugs (e.g., NSAIDs, corticosteroids)
- mast cell tumors that are actually on the skin (they can release histamine, etc., leading to hyperacidity in the stomach).
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.
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.
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!
This is good information to know! We learned this from our pediatrician when one of our kids was sick.
This definitely sounds like an emergency. I would probably think the gritty substance was dirt! My dog is always getting into dirt.