Vomiting and regurgitation

Puking isn’t a pleasant topic to talk about, but it is an important one. Most pet owners are familiar with cleaning vomit off the carpet, or stepping in cat sick in the middle of the night. There are many different reasons our pets might vomit and regurgitate. It is important to be able to differentiate vomiting from regurgitation, understand some causes of vomiting and regurgitation, and when to seek veterinary care for a vomiting or regurgitating pet.



Vomiting requires active abdominal effort, meaning the pet will heave and may retch before expelling anything. The vomitus will contain gastric and intestinal contents, and may contain bile. The food may be partially digested, depending on how long it has been in the digestive tract.


Regurgitation is a passive process, meaning it requires no abdominal effort and the pet will not heave beforehand. It may be sudden, and it may happen right after eating or drinking. Regurgitated material is composed of esophageal and gastric contents and does not contain bile. Usually, the food is undigested.

Canine vomitusNotice that undigested peas and carrots are still visible, but the owner did observe active abdominal effort when the dog vomited this meal
Feline vomitusNotice that the food has been partially digested
Regurgitated food and water from a dog with megaesophagusNotice that the kibble is undigested

Causes of vomiting


Food gorging

Pets who eat too much, too quickly (gorge on their food) may sometimes immediately vomit or regurgitate their meal. To learn more, visit Food gorging.

Dietary indiscretion

Vomiting is a common outcome of dietary indiscretion, meaning a pet has eaten something they are unused to eating. This may include the trash, another pet’s food, or even a new treat.

Dietary sensitivity

This may include an adverse reaction to food, a food intolerance, a food allergy, or a food sensitivity. To learn more, visit Food allergies.


Bilious vomiting syndrome

This condition is a fairly common one among dogs, and has even been seen in cats. Certain pets, when they have not eaten in several hours and are expecting a meal, will vomit bile. Of the many reasons for vomiting, bilious vomiting syndrome is a fairly easy condition to diagnose and manage.

Foreign body

Something that is not food gets into the digestive tract, it is known as a foreign body. Foreign bodies are often bones, toys, sticks, or other household items pets should not eat. Foreign bodies can cause obstructions, perforations, intestinal plication, and intussusception, and they often require surgical removal.

Normal dogNOTE: black dotted line = diaphragm, green = stomach, blue = duodenum (intestine)Drawings are not to scale
Dog with two GI perforationsA perforation happens when a sharp foreign body pokes through the stomach/intestinal lining.
Dog with intestinal plicationNOTE: red = ball-and-string linear foreign bodyPlication is similar to when the drawstring is pulled out of a pair of sweatpants. The intestine becomes bunched up around the linear foreign body, usually a string of some kind.
Dog with intussusceptionNOTE: red = foreign bodyIntussusception is when the intestine telescopes on itself (think of pushing back your sleeves) and therefore is unable to move contents along properly.


This term literally means inflammation of the stomach and intestines. The inflammation can have many different causes, but it usually leads to abdominal discomfort, nausea, and vomiting.

Gastric ulcers

Stomach ulcers form when there is a pH imbalance in the stomach, leading to increased acidity and tissue damage. Ulcers can cause abdominal discomfort and vomiting.

Motility disorders

This term means there is something wrong with the movement of the digestive system; either the stomach is not emptying properly, or the intestines are not moving digesta along like they should. Therefore, the digesta may back up into the stomach and have nowhere to go, leading to vomiting.


Gastric dilatation-volvulus (“bloat”) does not cause vomiting, but it may cause retching. GDV is a severe and life-threatening condition. It happens suddenly and progresses very quickly. This condition involves the stomach filling with food and gas, then twisting and continuing to distend. It can rapidly become fatal, and always requires an emergency veterinary visit. Visit Canine bloat for more information.


There are many foods, plants, drugs, and household items that are potentially poisonous to pets when ingested and may cause vomiting. Visit What not to feed: unsafe foods for pets to learn more.


Pets should not receive medication of any kind unless it has been prescribed by their usual veterinarian. That being said, there are several medications your pet may be taking that can cause digestive upset, such as NSAIDs or chemotherapy. Talk to their usual veterinarian if you notice vomiting in relation to taking these medications.


Parasite burden

Gastrointestinal parasites like worms can cause vomiting and diarrhea. It is important to keep pets up-to-date on deworming and to have their feces tested for parasites yearly by the veterinarian.

Canine Parvovirus

CPV is a life-threatening illness in puppies, which is typically spread by adult dogs. Parvovirus causes vomiting, diarrhea, weakness, and lethargy in unvaccinated puppies. It is important to vaccinate adult dogs, and puppies when they are old enough, to reduce the spread of this disease.


Systemic means “whole body.” Some systemic causes of vomiting can include stress, endocrinopathy (e.g., adrenal or thyroid disease), neoplasia (cancer), renal (acute or chronic kidney disease), hepatic (liver disease), or pancreatitis (inflammation of the pancreas).

Causes of regurgitation


Cranial nerve disease

Damage to the nerves that control swallowing can cause regurgitation.

Motility disorders

Disease of the muscles that contribute to swallowing can cause regurgitation.

Foreign body

When foreign material is caught in the pharynx, food may be unable to pass and therefore may be regurgitated.



Inflammation of the esophagus may be caused by:

Anesthetic-associated reflux

When undergoing a routine anesthetic procedure like a dental cleaning or a castration, the animal may regurgitate stomach contents into the esophagus, thus causing irritation. The next time animal swallows, it causes more pain and irritation, leading to regurgitation, and starting a vicious cycle of esophagitis and regurgitation. This condition is fairly common, but veterinary practices are aware and do all they can to prevent it.


Many drugs or toxins can be irritating to the esophagus when ingested and can thus cause regurgitation. Again, do not administer medications to your pet without first consulting their veterinarian. Seek veterinary attention if you know your pet ingested a toxin.

Esophageal stricture

Esophageal stricture happens when there is an insult to the inner lining of the esophagus, most typically esophagitis. If the damage is severe enough, the esophagus may become very narrow and form scar tissue in the inner walls, preventing food from passing into the stomach.

Esophageal obstruction

A foreign body obstruction is a common cause of regurgitation in pets. Again, this is when something becomes lodged in the esophagus and prevents food material from passing. Esophageal obstructions can cause severe damage to the inside of the esophagus, and may require surgery to remove the offending item.

Other esophageal obstructions can be caused by something compressing the esophagus from the outside, such as a mass or enlarged lymph node in the chest cavity.


Megaesophagus is the most common cause of regurgitation in animals. There are several causes of megaesophagus, both congenital (i.e., the pet was born with it), and acquired (i.e., the pet contracted the condition later in life). Depending on the cause, the treatment of megaesophagus can vary widely.

Vascular ring anomaly 

Persistent right aortic arch (PRAA) is the most common vascular ring anomaly of animals. Pets with this condition regurgitate because their esophagus is being constricted from the outside by the vascular ring. This condition can look like megaesophagus, but the treatment is quite different. 

Normal dogNOTE: pink = esophagus, green = stomach, white dotted line = diaphragmDrawings are not to scale
Dog with a vascular ring anomalyNOTE: yellow = vascular ring
Dog with megaesophagus



Just like people, pets can get gastroesophageal reflux disease. With GERD, the stomach contents are refluxed into the esophagus, causing esophagitis, pain on swallowing, and a cycle of regurgitation and increased irritation. Like with people, GERD can be medically managed in pets.

Diaphragmatic hernia

A diaphragmatic hernia is when the contents of the abdomen enter the chest cavity. Stomach, intestines, and even other organs like the liver and spleen may be involved. One sign of a diaphragmatic hernia may be regurgitation. These hernias usually require surgery to repair.

Normal catNOTE: blue = lung field, red = heart placement, white dotted line = diaphragm, green = stomach and duodenum, brown = liver, pink = spleen
Cat with a diaphragmatic hernia

Consequences of prolonged vomiting or regurgitation

Chronic vomiting and regurgitation disorders can cause weight loss, nutrient deficiencies/imbalances, acid-base disorders, dehydration, and aspiration pneumonia. Therefore, it is imperative that pets with chronic vomiting or regurgitation visit a veterinarian for diagnosis and treatment

When to seek veterinary attention

Vomiting/regurgitating more than once

Pets who are chronically vomiting or regurgitating (i.e., it happens often, and has been going on for longer than a few days) should see a veterinarian promptly. If a pet has prolonged vomiting or regurgitation (i.e., more than once in a short time frame), they should be brought to the veterinarian.

Signs of illness

Pets who have blood in the vomitus or regurgitated should see a veterinarian immediately. If vomiting or regurgitation is accompanied by difficulty breathing, behavioral changes, lethargy, collapse, or other signs of illness, the pet should be brought to an emergency veterinary hospital.


The veterinarian will likely suggest various diagnostic tests to determine the cause of vomiting or regurgitation. This may include blood work, fecal testing, radiography (x-rays) with or without contrast, a fluoroscopy “swallow study,” or endoscopy.


It is important to follow the veterinarian’s advice for treatment of vomiting or regurgitation. Sometimes, the best way to help the pet is with surgery or lifelong medications. Following veterinary recommendations will ensure your pet will be healthy and comfortable long-term.

If your pet has a one-time incident of vomiting or regurgitation, or if you are absolutely certain there was dietary indiscretion or that your pet simply ate too fast, you may manage them at home. First, it is a good idea to call their usual veterinarian and to make sure this is recommended. For single incidents, veterinarians usually recommend withholding food and water for several (about 6) hours. Then, you may offer a small portion of bland diet (e.g., boiled chicken and rice, or a therapeutic veterinary diet) and a bit of water. If the pet vomits or regurgitates again, seek veterinary care. If they keep the meal down, wait several hours and offer another small meal. You can gradually return to their normal diet and amount over the course of 1-2 days. It is important that you do not feed chicken and rice as the sole diet long-term, as is not complete and balanced and can therefore cause nutrient imbalances and illness. It is also important to refrain from administering any medications to your pet (even over-the-counter ones) without first consulting with their usual veterinarian.


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