Sick Beagle

Vomiting is the forceful emptying of the stomach. It is usually a sign of a medical condition, ranging from motion sickness to parasites to poison ingestion to cancer, and can strike any pet. Prolonged vomiting leads to dehydration. Treatment aims to control the vomiting and resolve the primary cause. A safe environment, healthy diet, routine veterinary care, and routine blood work will go a long way toward preventing the things that cause vomiting.


Vomiting is defined as the forceful emptying of the stomach’s contents. It is caused by a signal from the brain to the stomach that originates in a part of the brain known as the emetic (or vomiting) center.

Vomiting initially developed because it helped save animals from poisoning. Nerves in the abdomen or certain substances in the bloodstream indicated to the brain that the animal may have eaten something toxic, and vomiting helped rid the body of the toxic substance. Over time, many more triggers began to induce the brain to signal vomiting. Prolonged vomiting is dangerous because it can lead to life-threatening dehydration.

Primary stomach or intestinal diseases that can cause vomiting include:

  • Parasites
  • Toxins
  • Foreign bodies
  • Spoiled food
  • Food allergies
  • Stomach ulcers
  • Inflammatory bowel disease
  • Cancer
  • Constipation
  • Secondary or non-stomach disorders that can cause vomiting include:
  • Motion sickness
  • Thyroid disease (in cats)
  • Pancreatitis (inflammation of the pancreas)v Pyometra (uterine infection)
  • Kidney or liver disease
  • Canine parvovirus or distemper
  • Feline panleukopenia virus

Signs and Diagnosis

Before attempting to diagnose what is causing a pet to vomit, it is important to differentiate between vomiting and regurgitation. Vomiting requires abdominal effort (constriction of the abdominal muscles) and is the active expelling of stomach contents. In contrast, regurgitation is the passive elimination of contents in the esophagus that happens without nausea or retching. This distinction is important because the medical conditions that cause regurgitation are different from those associated with vomiting.

Once he or she is sure your pet is vomiting, your veterinarian will begin to approach a diagnosis and treatment. In order to narrow the list of possible causes, your veterinarian will consider your pet’s age and species. For instance, a young energetic dog who is vomiting is more likely to have eaten something it shouldn’t have, while a senior cat with weight loss, increased drinking, and vomiting is more likely to have a medical problem such as kidney disease or thyroid disease.

Your veterinarian will likely ask detailed questions regarding duration of sickness, weight loss, medications, changes in appetite, and timing of the vomiting with regard to meals. He or she will perform a thorough physical exam to determine if there is abdominal pain, dehydration, or other abnormalities suggesting the cause of the vomiting. You may want to take some of the vomit to the hospital, because the appearance of vomit can help with diagnosis. For example, vomit with black, coffee ground-like material indicates that the stomach may be bleeding.

Your veterinarian may also recommend laboratory tests on blood, feces, and urine. It may also be necessary to evaluate radiographs (x-rays) and perform an abdominal ultrasound. If your veterinarian suspects that the problem is limited to the stomach and intestines close to the stomach, he or she may recommend an endoscopic examination. This procedure requires anesthesia and involves passing an endoscope (a long tube containing a tiny video camera) down your pet’s esophagus to look into the stomach and intestines.

Affected Breeds

Any breed of dog or cat can experience vomiting.


Dehydration from prolonged or severe vomiting is an immediate concern, and it may be necessary to admit your pet to the hospital for fluid replacement while your veterinarian looks for a diagnosis. Treatment is aimed at controlling the vomiting itself (to prevent further dehydration) and at gaining control of or eliminating the primary cause of the vomiting.

Some causes of vomiting are easily treated, such as when a pet with an allergy to a certain food stops vomiting when his diet is switched. On the other hand, a pet with stomach cancer may need surgery, chemotherapy, or more prolonged and aggressive treatment.


Vomiting is a signal to the owner and veterinary team that something is wrong. If your pet vomits once, remove food and water for a few hours. Eating and drinking may cause the vomiting to continue instead of stopping after one episode. If your pet continues to vomit without anything to eat or drink, call your veterinarian. Do not allow your pet to eat grass. It does not necessarily benefit the pet and can cause additional medical problems.

Sometimes it is difficult to determine the cause of vomiting. This is especially true if a pet is not well supervised or has access to a variety of things that can cause vomiting. Watch what your pet eats and prevent his access to harmful substances. Routine physical examinations, fecal testing, and regular wellness blood work can permit the early discovery and treatment of medical conditions such as parasites, diabetes, kidney or liver disease, thyroid disease, and other conditions that can cause vomiting.

Join the Conversation

Like this article? Have a point of view to share? Let us know!