Causes of Vomiting

Since there are many more causes of vomiting than there are for regurgitation, gagging and hacking, and dropping food and water, I will discuss the latter three first.


Your dog may regurgitate his food because he has a problem with his throat, his esophagus, or the valve that restricts entry into the stomach from the esophagus.

The following are some of the causes of vomiting.

An object is stuck in the esophagus.A blood vessel is constricting the esophagus. This is known as vascular ring anomaly or VRA for short.

Megaesophagus, an abnormally large esophagus due to poor muscle tone in the walls of the esophagus. The coordinated contractions that move food from the throat down to the stomach don't work properly. The food doesn't enter the stomach as quickly as it should, so some of it comes back up.

Esophageal stenosis, which is a narrowing of the esophagus.A hiatus hernia, which is a tearing or large opening in the diaphragm that separates the abdomen from the chest cavity. This tear or opening allows part of the stomach to move up into the chest cavity.

This is a birth defect in certain breeds (you'll see repeated regurgitation by your puppy), and diseases that affect the nerves or muscles of adult dogs. One is the inherited form of myasthenia gravis, which occurs most often in Smooth Fox Terriers, Jack Russell Terriers and Samoyeds.

There is no effective treatment for the birth defect form, except to change the way you feed your puppy. Raise his food and water dishes to near head height so he can keep his head up while eating. This allows gravity to help move the food towards the stomach.

Also, feed him more often, giving him smaller amounts of high-calorie food rather than larger meals of low-calorie food just once or twice a day. This ensures that the food he is able to get into his stomach will provide enough nutrients for his growing body.

Beware of pneumonia if your dog has megaesophagus. Since food does not move quickly to the stomach, there is a greater risk of him inhaling some of it into his lungs, where it can cause pneumonia.

Gagging and Hacking

If your dog is gagging and hacking, this cough is caused by a problem with one of these:

  • the esophagus

  • the respiratory system; this includes not just the lungs, but the entire system, from the nasal sinuses down to the lungs

  • the heart (if the heart isn't pumping effectively, the slower passage of blood through the blood vessels of the lungs may allow fluid to seep from them into the lungs, which triggers a cough to expel the fluid).

Dropping Food and Water

If your dog can't pick up or hold food or lap up water, or if he repeatedly tries to swallow, he may have a problem with one of these:

  • the teeth

  • the nerves controlling the muscles that let him pick up food, chew or swallow

  • the brain, which is the controller and coordinator of the nerves for chewing and swallowing.

As mentioned earlier, the causes of vomiting are varied. The cause of vomiting can be obvious or obscure, simple or complex. Here's a rule of thumb that you can discuss with your vet. If your dog is vomiting more than three times in an hour, or more than six times in eight hours, call your vet or emergency animal clinic for advice.

I've categorized these causes of vomiting to make it simpler for you to determine, or try to determine, the cause of vomiting.

Simple and Obvious

"Dietary indiscretion," also known as "something he ate."

If the trash can is tipped over, or a garbage bag is torn apart, it's likely that he did indeed eat something that will be the causes of vomiting now.

Eating too fast. This is another of the very common causes of vomiting.

If I had a buck for every time my dog did this...!

Eating grass. Most dogs do it, and it can be a cause of vomiting because of it.

It's normal and something he'll recover from quickly.

However, if your lawn was recently sprayed with a herbicide or other pesticide, call your vet if you catch your dog eating that grass. She'll let you know whether you need to bring him in or watch for other signs of illness.

Causes of vomiting on an empty stomach

Also know as bilious vomiting, this usually happens first thing in the morning when the dog's stomach is empty. Talk with your vet for advice on dealing with this.

Medicines That Cause Vomiting

Pain relievers such as aspirin, Butazolidin (phenylbutazone), EtoGesic (etodolac) and Rimadyl (carprofen).

The following pain relievers are toxic to dogs. Never give any of these three to your dog, or any over-the-counter (OTC) medication that contains one of these drugs. They can cause kidney and liver damage.

  • Advil or Motrin (ibuprofen)

  • Aleve (naproxen)

Antibiotics are often a cause of vomiting

If you're giving your dog amoxicillin, cephalexin, tetracycline, Antirobe (clindamycin), Clavamox, and Flagyl (metronidazole) watch for vomiting afterwards.

The heart disease drugs Digoxin and digitoxin (Cardoxin or Lanoxin).

Lysodren (mitotane), which is given for Cushing's disease.

Chemotherapy drugs for treating cancer.

High doses of the steroids used when treating paralysis and severe spinal cord inflammation. The steroids used to control severe allergic diseases may cause upset, but their lower doses don't usually create a problem

More Serious Problems

If your dog has swallowed a poison, it may be coming back up. If you suspect any poison, call your vet for advice. See Household Poisons for more information on how to prevent poisonings around the home.

Kidney disease.

Liver disease.

Pancreatitis, which is often caused by eating foods that have too much fat in them (usually human foods). Check Toxic Foods for more on foods that can harm your dog.

Your dog throws up hours after he's eaten. Your veterinarian should investigate, as the food is not passing from the stomach to the small intestine properly.

There are several possible causes of vomiting, so your vet will have to diagnose the cause before prescribing a treatment.

"Foreign body obstructions," which is the term veterinarians use to describe an object a dog has eaten that is now blocking part of the digestive system.

If the object makes it into the stomach, it may be the cause of vomiting. If it passes into the small intestine, it may block passage and cause vomiting (but not always).

If you think your dog has swallowed something that could obstruct part of the digestive tract, contact your vet for advice.

If you see bright red blood in your dog's vomit, he may have a stomach ulcer. Since dogs don't get ulcers as easily as we stressed-out humans do, your vet will have to run tests to determine the cause of vomiting.

If your dog is older, he may be suffering from problems associated with age, including kidney problems and diabetes.

Head injuries and vestibular disease, which is a problem in the inner ear, can also be a cause of vomiting.

As you can see from the list above, the causes of vomiting are numerous. If vomiting persists, or you think it may be more than just "dietary indiscretion," consult your veterinarian at once.

The causes of vomiting are many and varied.

from The Causes of Vomiting to Dog Symptoms