Why Your Dog Keeps Throwing Up
Why dogs vomit, from garbage and poisons to pancreatitis and kidney disease, how vomiting differs from regurgitation, what a vet checks for short-term and long-term vomiting, and the signs that cannot wait, from the Merck Veterinary Manual. A reading guide, not veterinary advice.
AI illustration This is a reading guide to what veterinary sources say about vomiting in dogs. It cannot tell you why your dog is vomiting; only your vet can. If your dog vomits and seems unwell, or may have eaten something toxic, call your vet or an emergency clinic now. ASPCA Animal Poison Control answers around the clock on (888) 426-4435; a fee may apply.
The short answer: vomiting is a sign, not a diagnosis. The Merck Veterinary Manual lists digestive disease, kidney or liver failure, pancreatitis, nervous system disorders, and swallowed irritants and poisons among the causes. A short bout with no other signs is handled differently from vomiting that keeps coming back. Vomiting with blood, pain, weakness or fever needs a closer look.
Is It Really Vomiting?
Tell your vet exactly what you saw, because the two look alike but point to different places:
| Vomiting | Regurgitation | |
|---|---|---|
| Before it | Nausea, drooling, retching | Usually no warning |
| How it comes up | Forceful contractions of the belly muscles and diaphragm | Passively, with no effort |
| What comes up | Contents of the stomach and upper small intestine | Undigested food and fluid, sometimes in a tube shape like the esophagus |
| Often seen with | Coughing or difficulty breathing |
All of this is from Merck’s chapter, which notes that regurgitation is more often linked with coughing and breathing trouble than vomiting is. Problems of the esophagus have their own chapter in the Merck Veterinary Manual.
A Short Bout With No Other Signs
Merck defines short-term vomiting as less than 3 to 4 days with no other signs. For that, the vet usually starts with:
- Questions about what the dog could reach, including garbage and poisons, so think back before the visit.
- An examination of the belly and mouth, and a rectal check for blood or things the dog should not have eaten.
- X-rays for most vomiting dogs, because they can show life-threatening problems such as a swallowed object. Blood, urine and stool tests may follow.
If nothing serious turns up, easing the signs may be all the dog needs. The usual plan Merck describes is a short pause in food. Then come tiny amounts of easily digested food, about a teaspoonful, and then a slow return to normal meals. Water is a different matter: Merck warns it should not be withheld unless the dog is getting fluids from the vet. Vomiting already dehydrates, and too much or too little food or water at this stage can hurt the dog. So follow your own vet’s instructions rather than a general plan.
Vomiting That Keeps Coming Back
Merck calls for a more detailed workup when any of these is true:
- The vomiting is long-term.
- It happens more than once or twice a day.
- It comes with blood, abdominal pain, depression, dehydration, weakness, fever or weight loss.
The workup can include endoscopy and biopsies of the stomach and small intestine, ultrasound, CT or MRI. Treatment aims at the cause, plus correcting dehydration and salt imbalances. Repeated vomiting can itself cause weakness, weight loss and dehydration, which is one reason not to wait it out.
Related Reading
- Dog food for pancreatitis, one of the causes on Merck’s list
- Why dogs eat grass, and why the grass is rarely the problem
- Food for dogs with sensitive stomachs
- When to go to an emergency vet
