There are many different reasons your dog might be vomiting. Whether it's from illness or poisoning, parasites, or even just from eating too fast, learn to recognize the signs of something serious so you can get your pup the help he needs to feel better fast.

Dogs vomit for a whole lot of reasons that range from simple mistakes to serious diseases, but pet owners can play a key role in getting to a diagnosis. Taking note of details like what your dog has eaten, when he vomited, and what the vomit looked like can help your veterinarian pinpoint the underlying problem. And while many cases can be treated at home, if you're feeling unsure about your dog vomiting, a quick call to your veterinarian can help you decide what to do next. 

Reasons Dogs Vomit

Before we get to why dogs vomit, let's cover what vomiting is and isn't, because it's often confused with regurgitation. Here's how the Merck Veterinary Manual differentiates the two:

Vomiting is the forceful ejection of the contents of the dog's stomach and upper small intestine. It tends to consist of partially digested food and a yellow fluid called bile, but it can also be watery and foamy. You might see your dog drooling or gagging or notice the muscles in his stomach and chest contracting before vomiting. 

Regurgitation also releases food and fluids, but they are coming from the esophagus (the canal that connects the throat to the stomach) and tend to be undigested, covered in a slimy mucus, and in a tube-like shape (reflecting the shape of the canal). The action doesn't require effort or stomach muscle contractions and tends to occur right after eating or drinking. 

There's something else vomiting isn't: a diagnosis. Instead, it's a clinical sign that can result from a long, diverse list of problems and diseases. 

According to Gonzalo Erdozain, DVM, MPH, of Kansas City Veterinary Care in Kansas City, Mo., the vast majority of vomiting cases he sees are caused by dietary indiscretions, meaning the pup has eaten something he shouldn't that's resulted in an upset stomach. This broad category includes foreign objects (e.g. toys, bones, socks) that block the intestines, toxic products, and irritating foods or plants. "Usually," he explains, "the cases we see are caused by dogs that have eaten table scraps, trash, or something out in the yard."

Causes of Dog Vomiting

Erdozain says other common causes of vomiting include:

  • Intestinal parasites (e.g. tapeworms, roundworms)
  • Gastrointestinal diseases (e.g. constipation, pancreatitis, gastroenteritis, stomach ulcers)
  • Endocrine diseases (e.g. hypoadrenocorticism, diabetes mellitus)
  • Systemic diseases (e.g. kidney disease, liver disease, food intolerance, food allergy, cancer)

Still, the cause of your pet's vomit may be as simple as eating too fast, a new diet, or a ride in the car—that's right, pets can get motion sickness, too. 

dog laying on hardwood floor in living room; why is my dog vomiting?
Credit: mgstudyo / Getty

When Is It Time to Call the Vet?

"As a general rule of thumb: When in doubt, call your veterinarian," Erdozain says. "That's what we're here for." You should be able to speak with either your veterinarian or a veterinary technician who will consult with the veterinarian and help you decide if your dog needs to be seen. 

If your dog has only vomited once and is otherwise doing well, Erdozain tends to advise withholding food for 12 hours to see how he does. But if your dog has vomited several times in one day, has vomited once per day for several days, or has vomited only once but is acting like he doesn't feel well, Erdozain says he should be seen by a veterinarian. 

Diagnosis and Treatment of Dog Vomiting

Getting a thorough history is key in vomiting cases, so be prepared to answer questions like:

  • When did your dog vomit? 
  • How many times did he vomit?
  • How much did he vomit?
  • What did the vomit look like? 
  • Has this happened before?

"Some conditions can be diagnosed with history alone, like the dog who's eaten two pounds of chocolate," Erdozain says. "But other times, it's not as straightforward, and more diagnostic tests are needed." Your dog may need a physical exam, bloodwork, a urine analysis, x-rays, or ultrasound imaging before a diagnosis can be made. 

Treatment is tailored to the diagnosis, and because there are many potential causes of vomiting, there are many potential treatments as well. Erdozain says you may be able to treat your pet at home by withholding food for 12 hours, giving antinausea and antacid medications, and providing a bland diet for a few days. More serious cases may need inpatient hospital treatment, such as intravenous fluids and medications, regular monitoring, or surgery to remove any foreign objects. 

In the end, because vomiting can be a sign of so many different diseases and problems, Erdozain goes back to his rule of thumb: "When in doubt, don't hesitate to call your veterinarian's office." Your dog's veterinary team is always ready to partner with you on your pet's health.