Vomiting in Dogs: Causes, What to Do and What Tests

Vomiting in a dog is a common symptom with very different causes: from harmless overeating to poisoning and obstruction. It matters to tell a single vomit in an active dog from a worrying one — with blood, frequent, with lethargy. Let's break down why a dog is vomiting, when it is dangerous and what tests help find the causes.

Common Causes of Vomiting in Dogs

• Diet errors: overeating, gulping, a food change, table scraps.
• Poisoning and eating non-food items.
• Foreign body and intestinal obstruction.
• Infections and parasites.
• Organ disease: GI tract, pancreas, liver, kidneys.
• Motion sickness in transport.

When Vomiting Is Dangerous (Red Flags)

See a vet urgently if vomiting is:

• with blood (bright red or "coffee grounds") or repeated and unrelenting;
• accompanied by severe lethargy, abdominal pain, refusing food;
• combined with diarrhoea (dehydration risk) — see diarrhoea in dogs;
• unproductive (retching without bringing anything up) with a bloated belly — possible gastric torsion, an emergency;
• in a puppy or small/old dog — seek help sooner.

Vomiting White Foam, Bile or After Eating

White foam or yellow bile on an empty stomach (often in the morning) can come from irritation of an empty stomach — but repeated vomiting needs a work-up. Vomiting right after eating — overeating, gulping or food intolerance; vomiting hours later of undigested food is a reason for caution.

What to Do at Home (No Red Flags)

If the dog is active, vomited once, without blood: withhold food for a few hours, give water in small amounts (a large volume at once triggers vomiting), then a bland diet in small portions. Do not give human anti-emetics without a prescription. Repeated vomiting, blood, lethargy — see a vet.

What Tests to Run

Baseline — a complete blood count and biochemistry (inflammation, liver, kidneys, pancreas, dehydration); their interpretation is in dog blood test. If a foreign body/obstruction is suspected — ultrasound for dogs and cats. If the dog is also not eating — dog not eating.

To understand your pet's tests in plain language, upload the form (PDF or photo) to the pet results interpretation service. This helps you understand the result but does not replace a vet.

This article is informational. Diagnosis and treatment of your pet are the job of a veterinarian.