Before you read a list of causes, answer one question, because a vet will ask it first, and the answer changes everything that follows.
Did your dog heave?
Vomiting or regurgitation?
These look similar in a dark room at 5am and mean completely different things.
| Vomiting | Regurgitation | |
|---|---|---|
| Effort | Active, abdominal heaving, retching | Passive, it just falls out |
| Warning signs | Nausea, drooling, lip-licking, restlessness | None; often mid-walk or right after eating |
| Timing | Any time after eating | Usually soon after eating |
| What comes up | Partly digested, may contain bile | Undigested, often tube-shaped, coated in mucus |
| Points to | Stomach, intestines, or a systemic cause | Oesophagus |
Why this matters: vomiting sends a vet looking at the stomach, intestines, pancreas, kidneys and liver. Regurgitation sends them looking at the oesophagus, megaoesophagus, a stricture, a foreign body lodged on the way down. Different tests entirely.
If you are unsure, film it. A ten-second phone video of the event is worth more than any description you can give at the clinic, and every vet would rather see it than hear it.
Is this an emergency?
Go now, tonight, no waiting, if you see:
- Repeated retching that produces nothing, with a swollen, tight, drum-like belly. This is bloat (GDV) until proven otherwise. It is measured in minutes and it kills. Deep-chested dogs, Great Danes, German Shepherds, Dobermans, Labradors, are at higher risk, but it is not exclusive to them
- Blood in the vomit, or material that looks like coffee grounds. That is digested blood
- Known or suspected toxin, or something swallowed that should not have been
- Vomiting plus collapse, pale gums, or severe lethargy
- An unvaccinated puppy vomiting with diarrhoea, parvovirus until proven otherwise
- Cannot keep water down for more than a few hours, in any dog
- Repeated vomiting in a very small, very young or very old dog, less reserve, faster deterioration
Call the clinic today if: vomiting has continued more than 24 hours, there is weight loss, there is a known chronic condition, your dog is on medication, or the vomiting keeps recurring over weeks.
Watch at home if: one or two episodes, your dog is otherwise bright, drinking, has a soft non-painful belly, and there is no blood.
What causes vomiting in dogs?
Roughly in order of how often you will actually meet them.
Dietary indiscretion. The single most common cause. Something eaten off the street, out of a bin, off a plate. Usually self-limiting within a day.
Sudden diet change. Switching food overnight rather than across five to seven days.
Intestinal parasites. Common in India and frequently under-treated, especially in dogs with outdoor access. Worth a faecal test rather than a guessed dewormer.
Bilious vomiting syndrome. The classic picture: yellow foam, early morning, empty stomach, dog completely normal otherwise. Bile irritates the empty stomach overnight. Often resolved by a small meal last thing at night. It is formally a diagnosis of exclusion. It should be what remains after other causes have been ruled out, not the first thing you assume.
Motion sickness. Very common in young dogs, and largely outgrown.
Foreign body. Toys, cloth, bones, plastic, mango stones. Suspect it strongly when vomiting is persistent, nothing stays down, and the dog is uncomfortable. This is surgical and time-sensitive.
Toxins. In Indian households, most often chocolate, xylitol in sugar-free products, onion and garlic in quantity, rat poison, and pesticide residue.
Systemic disease. Kidney disease, liver disease, pancreatitis, Addison's, and, in an unspayed female, pyometra, which is life-threatening and presents with vomiting and increased drinking as often as with any obvious discharge.
Heat. In an Indian summer, vomiting alongside heavy panting and lethargy after time outdoors is a heat-stroke question, not a stomach question, and it is an emergency.
What to do at home for an uncomplicated case
For a bright dog that has vomited once or twice and has none of the red flags:
- Rest the stomach briefly, 12 to 24 hours without food is reasonable after vomiting. Do not extend it much further; prolonged fasting thins the intestinal lining and delays recovery.
- Water in small amounts, frequently. Never withhold it, but a nauseated dog that empties a full bowl in one go will bring it straight back. Small and often is the trick.
- Reintroduce food small and bland, boiled chicken and rice, a quarter portion, four to six times a day.
- Rebuild to the normal diet over three to five days.
- Write down every episode, time, what came up, what the dog had eaten. If this turns into a chronic problem, that record is the most useful thing you will bring to the clinic.
Do not give human anti-emetics or antacids without veterinary direction. And do not reach for metronidazole because it is in the cupboard from last time, the evidence on that habit is not kind.
When vomiting becomes chronic
Vomiting that recurs over weeks is a different problem, and it will not be solved by another round of bland food.
The usual path is a faecal examination, bloodwork including pancreatic markers, imaging, and, if those are unrevealing, a diet trial, and ultimately biopsy. That progression sounds daunting, but chronic vomiting with weight loss is exactly the presentation where waiting costs the most.
Bring to that appointment: your episode log, a video, the food label, and an honest list of everything else the dog eats, including treats, chews and whatever the household feeds without mentioning it.
The bottom line
Answer the heaving question first. Vomiting and regurgitation lead down different roads and telling them apart costs you nothing.
Then triage honestly. Most single episodes in a bright dog are a dog that ate something stupid. But unproductive retching with a swelling belly is one of the few things in this article where the difference between going now and going in the morning is the difference between a dog you keep and a dog you don't.
Vomiting a specific colour? Brown vomit has its own set of causes and its own danger sign, see dog throwing up brown liquid.