Vomiting in Dogs: What’s in the Vomit?
What can the content of your dog’s vomit tell you?

Dogs are built to vomit. No, I’m not kidding.
A part of the brain named the “vomiting center” is especially well developed in dogs, and they have a layer of skeletal muscle throughout the length of the esophagus that essentially allows them to vomit at will.
So, if your dog occasionally throws up but you can point to the reason why (e.g., he ate too much, he ate too quickly, he ate something yucky, you’re driving on a curvy road) and he’s perfectly normal in all other regards, you probably have nothing to worry about.
There are times, however, when vomiting can be indicative of a serious medical problem, which begs the question, “How is an owner supposed to know when to be worried and when to write off vomiting as a dog just being a dog?”
Paying close attention to exactly what a dog is doing and producing will usually reveal the answer.
If your dog exhibits any of the following symptoms, play it safe and call your veterinarian:
- vomiting more than once or twice in a day
- projectile vomiting (a sign of possible gastrointestinal obstruction)
- poor appetite
- diarrhea
- lethargy
- weight loss
- changes in drinking and urinary habits
- abdominal pain
- abdominal enlargement
But that’s not all.
An often overlooked method of determining whether or not a dog’s vomiting is serious is to examine the vomit itself.
I know, you’re thinking “gross,” but there really might be some good information in there. Here’s what to look for.
1. Nothing
As paradoxical as it may sound, a dog that is trying to vomit but nothing is coming up may be in the greatest danger of all. This is a classic symptom of gastric dilatation and volvulus (GDV or bloat), a life-threatening condition that necessitates immediate veterinary attention if an affected dog is to survive.
2. Bright red blood
If there is more than just the smallest streak of blood, call your veterinarian ASAP. It should go without saying that if a dog is bleeding from his gastrointestinal tract, he needs immediate veterinary attention.
3. Coffee Grounds
No, your dog didn’t just raid the garbage can, this material is partially digested blood, call your veterinarian ASAP.
4. Worms
Yes, dogs can vomit up gastrointestinal parasites. Roundworms are the most likely culprit, particularly in puppies. If your dog has just been dewormed, this is not an immediate cause for concern as long as he is happy, active, eating, drinking, and pooping. Continue with your deworming protocol. If your dog has not been dewormed recently, he needs treatment – call your veterinarian.
5. Frothy yellow or orange-tinged fluid
The froth is mucus mixed with other gastrointestinal fluids and the yellow-orange pigment comes from bile, which is secreted into the upper part of the small intestine. If your dog tends to vomit up fluid like this when his stomach is empty, he may have a condition known as “bilious vomiting syndrome.” Most cases can be managed by feeding more frequently throughout the day. Offering two or three small meals rather than one big one will usually do the trick.
6. Bright green material
Some types of rodenticides (poisons used to kill mice and rats) are died a bright green color. If you notice a green discoloration to your dog’s vomit, call your veterinarian immediately.
And while you’re poking around in the vomit, collect a sample to bring to your dog’s veterinarian should you decide to make an appointment.
The vet may not need it, but if they do (e.g., to test for a poison) you’ll be happy you didn’t throw it all away.
Related articles:
Symptoms to Watch for in Your Dog: Vomiting
What Happens in a Dog’s Body with Severe Vomiting?
Further reading:
Different Types of Dog Vomit, and What They Indicate