Vomiting in Cats
Veterinary & Aquatic Services Department, Drs. Foster & Smith

What is vomiting?
Vomiting is the forceful expulsion of stomach contents through the mouth. Vomiting involves the forceful contraction of stomach muscles; regurgitation does not. Both vomiting and regurgitation can occur right after eating or drinking, or up to several hours later.

What is the difference between vomiting and regurgitation?
In regurgitation, the food that is expelled comes from the mouth or esophagus, versus the stomach.

If my cat is vomiting, when should I call my veterinarian?
If your cat is bright and alert, and only vomits once, it is probably not necessary to call your veterinarian. Many cats will vomit after eating grass, for instance. If your cat vomits more than once or appears sick, call your veterinarian. Your veterinarian will ask you a series of questions to determine how severe the vomiting is. It will be helpful for your veterinarian to know when the vomiting started, how many times your cat has vomited, what the vomit looks like, and if your cat is uncomfortable. It is especially important that you call your veterinarian immediately if:

  • There is blood in the vomit
  • Your cat acts like he wants to vomit, but nothing is expelled
  • Your cat appears bloated or has a swollen abdomen
  • You suspect your cat may have eaten something toxic or poisonous
  • Your cat has a fever or is depressed
  • Your cat's gums are pale or yellow
  • Your cat is a kitten or has not received all his vaccinations
  • Your cat appears to be in pain
  • Your cat also has diarrhea

Do not give your cat any medications, including over-the-counter human medications unless advised by your veterinarian to do so.

How is the cause of vomiting diagnosed?
There are many causes of vomiting (See Table 2. Causes, Diagnosis and Treatment of Vomiting in Cats). It is important to determine the cause so the appropriate treatment can be given. Your veterinarian will combine information from you, the physical exam, and possibly laboratory and other diagnostic tests to determine the cause of the vomiting.

When cats vomit, their abdominal muscles contract very strongly multiple times before the food is actually ejected from the mouth. It may appear as though the whole body is involved in the effort. Often they will go through this process several times in a row.

Onset of symptoms: How suddenly the symptoms appeared is a good clue to what the cause of the vomiting may be. If the symptoms appeared suddenly, the condition is called "acute". If the symptoms remain over a long period of time (weeks), the vomiting is called "chronic".

Appearance of vomit: Distinguish vomiting from regurgitation (expelling food that has not yet reached the stomach; whether the vomit contains food, hair or just fluid; color of vomit; presence of blood or bile in the vomit.

Degree of nausea: As shown by such signs as licking or smacking of lips, drooling, swallowing, or gulping.

Timing of vomiting in relation to meals or drinking.

Severity: How often the vomiting occurs and whether it is projectile.

Presence of other signs: Fever, pain, dehydration, urinary changes, depression, weakness, diarrhea, or weight loss. Vomiting is often caused by diseases not directly related to conditions of the digestive tract, such as hepatitis, pancreatitis, diabetes, and kidney disease.

Medical History
Your veterinarian will ask about your cat's medical history including vaccinations, what type of wormer the cat has received and how often, contact with other cats, diet, any access to garbage or toxins, and any medications. The more information you can offer, the easier it will be to make a diagnosis.

Physical examination
Your veterinarian will do a complete physical exam including taking your cat's weight and temperature, checking the heart and respiration, looking in the mouth and under the tongue, palpating the abdomen, and checking for dehydration.

Laboratory and diagnostic tests
In some cases of vomiting, your veterinarian will recommend a fecal flotation. This is a test to check for parasites such as intestinal worms or Giardia. If a bacterial infection is suspected, a fecal culture and sensitivity are performed.

If the cat is showing signs of illness, a complete blood count and chemistry panel are often recommended. Special blood tests may also be conducted if certain diseases are suspected.

Radiographs (x-rays) are appropriate if a tumor, foreign body, or anatomical problem is suspected. Other diagnostic imaging such as a barium study or ultrasound may also be helpful. Examinations using an endoscope may be indicated.

For some diseases, the only way to make an accurate diagnosis is to obtain a biopsy and have it examined microscopically.

How is vomiting treated? Because there are so many causes of vomiting, the treatment will vary (See Table 2. Causes, Diagnosis and Treatment of Vomiting in Cats).

In many cases of vomiting in cats, it is recommended to withhold food for at least 24 hours, and provide small amounts of water frequently. Then, a bland diet such as boiled hamburger and rice is offered in small amounts. If the vomiting does not recur, the cat is slowly switched back to his normal diet or a special diet over the course of several days.

For some cases of vomiting, it may be necessary to modify the diet permanently. Special foods may need to be given as a way to avoid certain ingredients, add fiber to the diet, decrease the fat intake, or increase digestibility.

If intestinal worms are present, the appropriate wormer will be prescribed. Few wormers kill every kind of intestinal worm, so it is very important that the appropriate wormer be selected. In most cases it is necessary to repeat the wormer one or more times over several weeks or months. It is also important to try to remove the worm eggs from the environment. The fecal flotation test looks for worm eggs, and if no eggs are being produced, the test could be negative even though adult worms or larvae could be present. For this reason, in some cases, even if the fecal flotation test is negative, a wormer may still be prescribed.

If dehydration is present, it is usually necessary to give the animal intravenous or subcutaneous fluids. Oral fluids are often inadequate since they pass through the animal too quickly to be sufficiently absorbed.

Antibiotics are given if the vomiting is caused by bacteria. They may also be given if the stomach or intestine has been damaged (eg., blood in the stool or vomit would indicate an injured intestine or stomach) and there is a chance that the injury could allow bacteria from the digestive tract into the blood stream.

In some cases, medications may be given to decrease vomiting. As a general rule, these drugs should not be given if the cat could have ingested a toxin or may have a bacterial infection, so it is always important to have an accurate diagnosis before use of these drugs.

Table 1: Causes, Diagnosis and Treatment of Vomiting in Cats
Cause Example Cats Most at Risk Symptoms Diagnosis Treatment
Diet change Changing cat food brand Those switching from a consistent diet Usually no other signs of being ill History and physical exam; tests (eg., fecal flotation) to rule out other causes Withhold food as needed then switch to bland diet and then slowly back to normal diet
Food intolerance or sensitivity Sensitivity to or inability to digest or absorb certain foods such as milk or gluten   Sudden onset of diarrhea, sometimes with gas Monitor response to removing ingredient from diet and then adding it again (food trial) Withhold food as needed then switch to diet without the offending ingredient
Bacterial infection Salmonella, E. coli, Clostridia, Campylobacter Young cats or those who are immuno-suppressed Mild to severe bloody diarrhea with loss of appetite, depression, fever and vomiting Fecal culture and sensitivity Antibiotics; intravenous fluids and supportive care in more serious conditions
Hookworms   Kittens Diarrhea, vomiting, weakness, pale gums, dehydration, anemia, swollen abdomen, black and tarry stools Fecal flotation exam Multiple treatments with appropriate wormer; decontaminate environment
Giardia   Usually young cats or those who are immuno-suppressed Mild to severe soft diarrhea with mucus and a bad odor; weight loss, abdominal pain and vomiting; often intermittent ELISA test on feces; fecal flotation exam or microscopic exam of feces; difficult to diagnose - often need multiple samples over several days Metronidazole, albendazole or febantel; bathing and sanitation to remove Giardia from coat and environment. Reinfection commonly occurs.
Viral infections Panleukopenia (feline distemper) Young cats who have not received full series of feline distemper vaccinations and those who are immuno-suppressed Acute diarrhea, loss of appetite, fever, depression, vomiting, dehydration, abdominal pain History, physical exam, white blood cell count Intravenous fluids, antibiotics to prevent secondary bacterial infection, withhold food and water
Feline corona virus (FCoV) Young cats, cats in catteries Diarrhea and possible vomiting History and physical exam; tests (eg., fecal flotation) to rule out other causes; FCoV antibody test, electron microscopy or PCR None
Feline Infectious Peritonitis (FIP) Young cats, cats in catteries; may be genetic susceptibility in some breeds Diarrhea, fever, lethargy, loss of appetite, weight loss, vomiting History, physical exam, analysis of abdominal fluid, CBC and serum chemistry Supportive care
Idiopathic inflammatory bowel disease Granulomatous enteritis, eosinophilic gastroenterocolitis, or lymphocytic/ plasmacytic enteritis (LPE)   Chronic vomiting and diarrhea possibly with blood and/or mucus; sometimes straining, mild weight loss, and/or black and tarry stools History; physical exam; intestinal biopsy; tests (eg., fecal flotation) to rule out other causes Modify diet, wormers and antibiotics to treat or prevent hidden infections; probiotics; anti-inflammatory drugs; immunosuppressing drugs if no response to other treatment
Cancer Lymphoma, adenocarcinoma Middle-age or older Chronic diarrhea, weight loss, poor appetite; may see vomiting and dark, tarry stools History, physical exam, intestinal biopsy Chemotherapy or surgery depending upon the type tumor
Small intestinal bacterial overgrowth (SIBO); also called antibiotic resistant diarrhea   Cats with other intestinal diseases Intermittent watery diarrhea, poor growth or weight loss, increased gas, sometimes vomiting History; physical exam; intestinal biopsy; tests (eg., fecal flotation) to rule out other causes; ultrasound; blood tests (eg., serum folate and cobalamin, bile acids) Antibiotics (at least 4-6 weeks); modify diet
Obstruction Foreign body, intussusception, pyloric stenosis   Diarrhea, vomiting, loss of appetite; as progresses see depression possible, abdominal pain History; physical exam; x-rays; barium series; ultrasound; exploratory surgery Surgery
Pancreatitis   Adult cats, Siamese Fever, loss of appetite, lethargy, painful abdomen, vomiting History; physical exam;chemistry panel; other blood tests (e.g., Feline trypsin-like immunoreactivity) Restrict oral intake as needed; administer fluids; provide pain control and other supportive care; medications to control vomiting; maintain on low fat diet if necessary
Liver or Biliary Disease Hepatitis, biliary obstruction   Vomiting; yellow discoloration of gums and whites of the eyes History; physical exam; chemistry panel; other blood tests; x-rays and/or ultrasound; biopsy Medications and fluids to control effects of vomiting and liver disease; possible surgery depending on cause
Kidney Disease Pyelonephritis, glomerulonephritis Older cats Vomiting, increased thirst and urination History; physical exam; chemistry panel; urinalysis; x-rays and/or ultrasound Diet changes; medications and fluids to control effects of vomiting and kidney disease
Peritonitis Perforated intestine   Vomiting, painful abdomen; sometimes fever History; physical exam; chemistry panel; complete blood count; x-rays and/or ultrasound Antibiotics, fluids; medications to control vomiting; possible surgery depending upon cause
Pyometra (infection of the uterus)   Unspayed females Vomiting; fever, vaginal discharge History; physical exam; complete blood count; x-rays and/or ultrasound Surgical removal of uterus; medical treatment
Diabetes mellitus   Overweight cats Vomiting, increased thirst and urination; sometimes depression History; physical exam; chemistry panel; urinalysis Insulin therapy; dietary management; supportive care
Hyperthyroidism   Middle-age to older cats Increased appetite, weight loss, vomiting, hyperactivity, increased volume of stools with greasy appearance Blood test for T4 hormone Treatment of hyperthyroidism with methimazole, surgery, or radiation
Toxins Strychnine, ethylene glycol, lead, zinc, poisonous plants Outside cats and those left unattended or unsupervised Loss of appetite, depression, vomiting, dehydration, abdominal pain History and physical exam; tests (eg., fecal flotation) to rule out other causes; testing of blood, feces or vomit for presence of toxin; x-rays Depends on toxin
Medications Digoxin, erythromycin, chemotherapy   Vomiting History; physical exam; drug levels Medications to control vomiting; change drug therapy
Septicemia     Vomiting, fever History; physical exam; blood culture Antibiotics; supportive care
Hypo-adrenocorticism (Addison's disease)     Vomiting History; physical exam; chemistry panel; complete blood count Medications to control effects of hypoadrenocorticism
Gastritis Helicobacter infection; high blood urea nitrogen (BUN); stomach worm   Vomiting History; physical exam; endoscopy Medications to control vomiting and protect stomach; treat underlying cause; fluids, if necessary
Urinary tract obstruction   Male cats Straining to urinate but producing no or little urine, vomiting, licking genital area Physical exam Remove obstruction while under anesthesia; intravenous fluids and supportive care
Ulcers     Vomiting; blood in vomit; black, tarry stools History; physical exam; endoscopy or barium series Medications to control vomiting and protect lining of stomach and intestines; treat underlying cause; fluids, if necessary
Heartworm infection     Lethargy, weight loss, coughing, vomiting Blood testing, radiographs, echocardiogram Supportive care
Motion sickness     Drooling, vomiting while riding in a vehicle History; physical exam Medications to control vomiting
References and Further Reading

Cave, NJ. Chronic inflammatory disorders of the gastrointestinal tract of companion animals. New Zealand Veterinary Journal. December 2003;51(6):262-74.

Hall, EJ; German, AJ. Diseases of the small intestine. In Ettinger, SJ; Feldman, EC (eds.) Textbook of Veterinary Internal Medicine, Sixth Edition. Elsevier, St. Louis MO; 2005; 1332-1378.

Simpson, KW. Diseases of the stomach. In Ettinger, SJ; Feldman, EC (eds.) Textbook of Veterinary Internal Medicine, Sixth Edition. Elsevier, St. Louis MO; 2005; 1310-1331.

Twedt, DC. Vomiting. In Ettinger, SJ; Feldman, EC (eds.) Textbook of Veterinary Internal Medicine, Sixth Edition. Elsevier, St. Louis MO; 2005; 132 -136.

Twedt, DC. Don't miss these commonly misdiagnosed gastrointestinal diseases. Veterinary Medicine November 2006: 716-718.

Willard, MD (ed.) The Veterinary Clinics of North America Small Animal Practice: Gastroenterology Mellitus. W.B. Saunders Co. Philadelphia, PA; 2003.

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