If your dog threw up dark brown liquid, it can be alarming and unsettling.
This type of vomiting is not common, and while it could be something minor like food discoloration, it may also indicate a more serious underlying health issue.
We outline why a dog may throw up dark brown liquid, the common causes, and what steps you should take to keep your pet safe.
Dog threw up dark brown liquid: Why it happens
When a dog throws up dark brown liquid, it often indicates the presence of digested blood from internal bleeding, commonly caused by stomach ulcers, gastrointestinal injuries, or ingestion of toxic substances.
It may also result from eating feces, dirt, or food with dark dyes, but in more serious cases, it signals conditions like intestinal blockages, liver disease, or tumors.
The dark color typically comes from blood that has been partially digested, turning it brown and sometimes resembling coffee grounds.
Common Causes of Dog Throwing Up Dark Brown Liquid
1. Gastrointestinal bleeding
One of the most serious causes for when a dog threw up dark brown liquid is internal bleeding, particularly in the stomach or upper intestines.
This type of bleeding can turn the vomit a coffee-ground or dark brown color due to partially digested blood.
It often results from ulcers, trauma, or ingestion of irritating substances such as NSAIDs or steroids.
You may also notice other symptoms like lethargy, pale gums, or black stools.
Related: Dog throwing up and pooping (Causes and what to do)
2. Ingestion of feces or dirt
If your dog has recently been scavenging or eating feces (a behavior known as coprophagia) or soil, this can lead to a situation where your dog threw up dark brown liquid.
The color may simply reflect the content of what was consumed.
While this might seem less serious than internal bleeding, it’s still important to prevent access to such materials since they can carry parasites or toxins.
3. Toxin ingestion
Another reason why a dog threw up dark brown liquid could be due to poisoning.
Toxins such as chocolate, rodenticides, or household chemicals can cause internal bleeding or irritation, leading to dark brown vomiting.
Other signs to watch for include tremors, drooling, weakness, or collapse.
Many toxic substances affect the liver or kidneys and should be treated as emergencies.
4. Intestinal blockage
When a dog swallows something they shouldn’t—like a toy, bone, or cloth—it can result in an intestinal obstruction.
As the blockage prevents food and liquids from passing properly, the contents may ferment and be vomited up as a dark brown substance.
Dogs with blockages often show signs like abdominal pain, loss of appetite, straining during bowel movements, and continuous vomiting.
Related: Dog throwing up and not eating (Here’s why)
5. Ulcers in the digestive tract
Ulcers can form in a dog’s stomach or small intestine due to long-term medication use, stress, or chronic illness.
When these ulcers bleed internally, a dog may throw up dark brown liquid.
The appearance is usually thick and may contain small clots or a coffee-ground texture.
Other signs of ulcers may include weight loss, poor appetite, and visible discomfort after eating.
6. Parvovirus or severe infections
If your dog threw up dark brown liquid and is also experiencing bloody diarrhea, fever, and lethargy, parvovirus or another serious gastrointestinal infection could be to blame.
Parvo is especially dangerous in puppies and unvaccinated dogs.
The dark brown vomit may contain blood or digested tissue from the intestinal lining that has been severely inflamed.
7. Liver disease
Liver dysfunction can lead to vomiting of various colors, including dark brown.
This happens when the liver fails to properly filter toxins from the body, leading to gastrointestinal upset.
When a dog throws up dark brown liquid and also shows signs like jaundice, increased thirst, confusion, or seizures, liver issues may be at the root.
8. Constipation and fecal vomiting
In extreme cases of constipation or bowel obstruction, a dog might vomit material that resembles feces.
This is known as fecal vomiting and is always considered a medical emergency.
If your dog’s vomit smells strongly of feces and is dark brown in color, seek veterinary help immediately.
9. Tumors or cancer
Cancerous growths in the stomach, intestines, or other organs may also cause bleeding or tissue breakdown, leading to dark brown vomiting.
Tumors may disrupt normal digestion and cause secondary infections or blockages. Sudden weight loss, fatigue, or visible swelling can accompany this condition.
Related: Dog throwing up and drinking a lot of water (Here’s why)
10. Diet and food coloring
While less dangerous, sometimes the answer is simpler: a dog threw up dark brown liquid because of their diet.
Some kibble or treats contain artificial coloring or rich, dark ingredients like liver or beef.
If vomiting happens shortly after a meal and your dog is otherwise normal, this might be the reason—but monitor for recurrence or other symptoms.
What to do if your dog threw up dark brown liquid
Knowing how to respond when your dog throws up dark brown liquid can make a significant difference. Here’s what to do:
1. Observe and assess
Take note of how your dog is behaving. Is this a one-time episode, or is your dog vomiting repeatedly? Are they eating, drinking, and acting normally otherwise?
Note the consistency, smell, and any accompanying symptoms like diarrhea, lethargy, or weakness.
2. Check for poisoning
If you suspect your dog may have ingested something toxic—such as human medication, chocolate, grapes, rat poison, or household cleaners—do not wait.
Call your veterinarian or an emergency animal poison control center immediately.
3. Look at their gums and hydration
Gently lift your dog’s lip and check their gum color. Pale or white gums can be a sign of shock or internal bleeding.
Also, check for signs of dehydration such as sunken eyes, dry nose, and slow skin elasticity when pinched.
4. Do not offer food immediately
If your dog threw up dark brown liquid, avoid offering food right away. Wait a few hours and then try a bland diet like boiled chicken and rice.
However, if vomiting continues or if your dog refuses water or food entirely, call the vet.
5. Monitor bowel movements
Watch for changes in stool. Black, tarry stools (melena) suggest internal bleeding.
Diarrhea, mucus, or the presence of blood can help your vet determine the underlying issue.
6. Visit the vet
If vomiting persists, if your dog seems lethargic, in pain, or shows any other worrying symptoms, take them to the veterinarian.
Diagnostic tests like bloodwork, x-rays, or an ultrasound may be needed to identify what’s going on internally.
When to seek emergency veterinary care
Some signs require immediate attention. Don’t delay seeking emergency care if:
Your dog is vomiting frequently or uncontrollably
There’s blood in the vomit or it looks like coffee grounds
The vomit smells like feces
Your dog seems extremely weak, pale, or collapses
They have a fever or show signs of shock
There are additional symptoms like severe diarrhea, bloating, or seizures
Key takeaway
When a dog threw up dark brown liquid, the causes can range from relatively minor to life-threatening.
While dietary changes or ingestion of soil might explain the issue in some cases, it’s crucial not to ignore persistent vomiting or accompanying symptoms.
Dark brown vomit often indicates bleeding in the gastrointestinal tract, toxin exposure, or intestinal blockages—each of which needs swift veterinary evaluation.
Pay close attention to your dog’s behavior, stool, and eating habits.
When in doubt, consult with your veterinarian to rule out serious causes and begin proper treatment.
Timely action can make all the difference in helping your dog recover and stay healthy.