Vomiting in Animals

Vomiting is one of the most common reasons that animals are presented to a veterinary clinic for examination. Unfortunately, vomiting is not a specific sign for any one problem. In fact, vomiting can be the result of many very different things including dietary indiscretion, metabolic diseases, motility disorders, obstructive diseases, inflammatory processes, 

neoplasia/cancer, food allergies, and parasites, among others. Thus, a thorough history and physical examination are necessary to gain important clues as to the cause of the vomiting and to determine what tests are necessary for an accurate diagnosis. 

The first part of this article will discuss some of the most common causes of vomiting. The second part will look at the different diagnostic testing options needed to diagnose these conditions. 

CAUSES OF VOMITING

Dietary Indiscretion and Overindulgence are probably the most common reasons for acute vomiting. Pets that have gotten into the trash or have been given table scraps or human foods commonly experience temporary vomiting. For some animals, any change from the normal diet can result in vomiting while other animals can handle foods outside of 

their normal regimen.

Hairballs are more common in cats due to their frequent grooming behavior. However, they can occur in dogs. Animals with hairballs may cough or retch with or without producing the offending hairball. If the hairball causes an obstruction, the vomiting will often worsen and the animal will become sick.

Physaloptera or the stomach worm is a frequent, yet under diagnosed, cause of chronic vomiting in dogs and cats. It is obtained when animals eat bugs, grubs, or beetles or frogs, birds, or rodents that are carrying the parasite. Animals with this parasite may have severe vomiting episodes despite otherwise normal behavior.

Constipation, if severe enough, can result in vomiting. Many animals will stop eating prior to the onset of vomiting from constipation but some will continue to try to eat despite the fact that their GI tract is essentially full.

Feline Hyperthyroidism can result in vomiting that is associated with a voracious appetite and weight loss. If it is left untreated, hypertension, blindness, liver damage, and heart disease can result. 

Foreign Bodies are non-food items that become ingested and can lodge within the GI tract. Some examples of commonly ingested foreign bodies include toys, rocks, strings, and clothing items. They can be partially obstructive or fully obstructive. Animals with fully obstructive foreign bodies are typically much sicker than animals with partial obstructions. 

Stomach or Esophageal Ulcers or Erosions can result from certain medications or chronic vomiting. Sometimes ulcers can result from unknown causes. An erosion is a superficial ulcer. Either can cause vomiting.

Helicobacter is a spiral-shaped bacteria that can be found in the stomachs of normal and vomiting animals. In humans, this bacteria has been associated with stomach ulcer formation. This association has not been proven in animals at this time. However, animals with clinical signs and the presence of Helicobacter will often improve if the bacteria are eliminated.

Food allergy, food intolerance, and food aversion can all result in persistent or intermittent vomiting. Because there are no reliable tests for these problems, diagnosis can often be difficult. 

Pancreatitis or inflammation of the pancreas can result from the ingestion of greasy meals, trash, or certain medications. It is often accompanied by diarrhea and can be acute or chronic.

Chronic Kidney Failure is a common cause of vomiting in older animals. Affected animals may or may not have a decreased appetite, weight loss, and increased thirst in addition to the vomiting. Chronic renal failure is often the result of years of repeated small amounts of damage to the kidneys but it may be associated with heart disease as well.

Acute Renal Failure is a common cause of vomiting typically in younger animals. Certain toxins, drugs, and infectious agents can cause acute renal failure.

Liver Diseases can cause vomiting in some individuals but not in others. There are many different liver diseases including but not limited to hepatic lipidosis, chronic active hepatitis, cholangiohepatitis, and cirrhosis. 

Idiopathic or Geriatric Vestibular Disease causes severe incoordination, dizziness, falling, head tilting, and nystagmus (rapid side to side eye twitching) in addition to nausea/vomiting. 

Addison's disease or Hypoadrenocorticism is an uncommon, life threatening condition in which vomiting can be one of several signs. It is usually diagnosed in young animals and can be successfully treated if diagnosed properly.

Morning Sickness in the earliest stages of pregnancy is uncommon but can cause vomiting in some animals. 

Inflammatory Bowel Disease is a collection of conditions that can result in chronic vomiting. More often, animals with inflammatory bowel disease have diarrhea. 

Cancer or Neoplasia of the liver, kidneys, pancreas, intestine, or brain can result in vomiting. Intestinal obstruction by a mass or tumor can also result in vomiting.

Megaesophagus or an enlarged flaccid esophagus results in regurgitation of undigested food. Regurgitation is technically different from vomiting in that regurgitation vomiting, especially if it does not happen right after eating.

While this is a fairly large list of common causes of vomiting in animals, it is not a complete list. There are other causes. Because vomiting has so many different causes, there is not a single diagnostic test that will yield a firm diagnosis in all cases. It is quite likely, especially in chronic or complicated cases, that several diagnostic tests will be necessary to identify the source of the vomiting. Different diagnostic tests give different types of information. Thus, knowing the pros and cons to each diagnostic test as well as when a test can be useful is essential. Next we will look at the tests used to sort out these various causes.

VOMITING DIAGNOSTICS

History. A detailed history is an important first step to diagnosing the cause of vomiting. Information on the duration of vomiting, the relationship of vomiting to eating, and the overall condition of the patient can all give important clues and point towards the cause. In some instances, a history alone can be highly diagnostic. For example, if the owner saw their dog eat a pair of shorts two days earlier and the dog has been vomiting ever since, the diagnosis is likely a GI obstruction with a foreign body. If the history is not diagnostic, it can help determine which tests should be conducted.

Physical Examination. Like a complete history, a thorough physical examination can give important clues that lead to a diagnosis. For example, a vomiting cat that has a palpable nodule in its neck and a heart murmur is likely to be diagnosed with hyperthyroidism. The physical examination will also help determine what tests should be conducted. 

Bloodwork. Two general panels of bloodwork are often used to rule out several different metabolic causes of vomiting as well as provide important clues about the overall health status of the animal. A CBC, or complete blood count, looks at the cells. This panel will count the red cells, white cells, and platelets. A chemistry panel will look at several different organs, such as the liver, kidneys, pancreas, and thyroid glands, as well as provide information on electrolytes, protein levels, and blood sugar. 

Routine bloodwork is inexpensive and minimally invasive and can rule out many of the different causes of vomiting so it is often run early in the diagnostic process. Bloodwork is good for diagnosing kidney, liver, pancreas, and thyroid abnormalities. It can also given an indication of inflammatory or infectious conditions.

Plain Radiographs/X-rays. Radiographs allow us to see important structures on the inside of the body. Determination of the relative size and position of the major organs can provide important information on the vomiting animal. Excessive amounts of gas within the bowel can provide evidence of decreased motility and possibly point to an obstructive cause. Dense foreign objects, such as metal or dense plastics, can often be seen within the GI tract on plain radiographs. 

Radiographs are inexpensive, non-invasive, and easy to take so they are often done early in the diagnostic process. Plain radiographs are good for diagnosing some masses and foreign bodies. 

Barium Series. Barium is a liquid contrast media that appears solid white on radiographs. Barium is given alone or with food and can increase the diagnostic accuracy of radiographs by outlining objects and structures that do not show up on plain radiographs. In addition, taking a sequential series of radiographs can allow the determination of decreased GI motility. 

A barium series is easy to do but takes at least 4-6 hours. If the animal has frequent and/or severe vomiting that will not allow for the retention of the barium, it may not be a helpful test. Barium is good for diagnosing megaesophagus, foreign bodies, and decreased motility.

Treatment Trial. Treatment trials for certain suspected disorders or in patients that only have minor clinical signs can serve as a means of diagnosis. For example, a persistent hair ball problem in a cat can cause intermittent vomiting. A treatment trial with a hairball medication can eliminate clinical signs and result in a presumptive diagnosis. Broad spectrum deworming for parasites, such as physaloptera, the stomach worm, can eliminate clinical signs in affected patients as well.

For some conditions, such as food allergy, food aversion, and food intolerance, there are no reliable diagnostic tests. The only way to diagnose these problems is to feed a novel diet for 2-3 months. If the vomiting resolves during this time frame, the original food is then restarted. If the vomiting reoccurs, the animal most likely has a food issue.

Treatment trials are often inexpensive and may or may not be easy to complete. In some instances they can be 100% successful and can result in the cessation of vomiting. In other instances, treatment trials may not work resulting in a delay of clinical diagnosis.

Ultrasound. Ultrasound alone is not often diagnostic for many of the causes of vomiting. It is often used in conjunction with many of the other tests listed here. Ultrasound is good to look within certain solid structures, such as the liver. It is also good to verify the origin of suspicious masses. In some instances, a needle biopsy can be taken with ultrasound guidance.

Ultrasound is easy and non-invasive but requires the use of expensive, specialized equipment. 

Endoscopy. An endoscope is a long tube with a light source and a camera. It can be inserted into the mouth and passed into the stomach and small intestine allowing for the direct examination of the esophagus, stomach, and small bowel. Foreign bodies can often be removed without traditional surgery with the endoscope. If the cause of vomiting is not readily apparent with direct examination, multiple small biopsies of these areas can be obtained via the endoscope. 

Endoscopy allows for a lot of information to be obtained and is minimally invasive. There is minimal recovery time. Animals that have endoscopic procedures can often go home and resume their normal life the same day as the procedure. There are only two real disadvantages to endoscopy. First, the entire length of the GI tract cannot be examined with the scope. The upper GI tract can be examined via the mouth and the lower GI tract can be examined via the rectum but the middle portion will be unable to be reached. Second, areas outside of the bowel cannot be visualized with the scope. Endoscopy can diagnose GI ulcers and erosions, physaloptera, foreign bodies, stomach or intestinal cancers, Helicobacter infections, and inflammatory bowel disease.

Exploratory Laparoscopy. A laparoscope is also a tube with a light source and a camera. Instead of being placed inside of the GI tract, it is placed through the abdominal wall and into the abdominal cavity. It can allow direct visualization of all 

the abdominal organs. In addition, full thickness biopsies of liver, pancreas, spleen, stomach, and intestine can be done with the laparoscope. 

Laparoscopy allows for the full evaluation of the abdominal cavity with two to three very small incisions. Recovery time is minimal and most animals go home the same day. The main disadvantage is that it is more expensive than some of the other diagnostic methods. Many different conditions can be diagnosed and even treated with exploratory 

laparoscopy.

Exploratory Surgery. Exploratory surgery allows for the full examination of the entire abdomen through a large incision. Removal of foreign bodies, relief of GI obstructions, biopsies, etc. can all be done during exploratory surgery. 

Exploratory surgery is expensive and invasive. Animals will often need several days to recover from surgery. For animals that have become rehabilitated from chronic vomiting, recovery can be long and hard. Many different conditions can be diagnosed and treated with exploratory surgery.

***The information provided here is for educational purposes only. It is not intended to take the place of an examination and diagnosis by a licensed veterinarian. As always, if you have questions or concerns regarding the health of your pet, please consult with a veterinarian.***

The information provided is for educational purposes only and is not intended to take the place of your regular veterinarian. Please do not hesitate to contact your regular veterinarian if you have questions regarding your pet.