Vomiting in Cats

At a glance

About: Vomiting is common in cats and is a symptom and not a disease in itself, it occurs in three stages, nausea, retching and vomiting.


  • Dietary indiscretion
  • Infection (viral, bacterial, protozoal)
  • Intestinal parasites
  • Gastrointestinal blockage
  • Poisoning
  • Neoplasm
  • Gastric ulcer
  • Inflammatory bowel disease
  • Hyperthyroidism
  • Kidney disease
  • Liver disease
  • Motion sickness
  • Diabetes
  • Pancreatitis

Diagnosis: Baseline tests to evaluate the overall health of your cat, fecal tests, diagnostic imaging and additional tests depending on the veterinarian’s index of suspicion.

Treatment: A bland diet to rest the gastrointestinal tract, supportive care such as fluids and nutritional support and specific treatment depending on the underlying cause.


Medically known as emesis, vomiting is a chain of events of which the end result is the forceful ejection of the stomach contents and is one of the most common reasons cat owners take their cat to the veterinarian.

There are a number of possible causes of vomiting in cats, it may be acute (sudden onset), chronic (over a period of time) or sporadic (coming and going). Acute vomiting is defined as vomiting which has been present for less than one week and is usually the result of a single insult to the stomach and is self-limiting, chronic vomiting lasts longer than a week, can be intermittent or persistent in nature.


The most common cause of vomiting is swallowing indigestible products (hair, grass) which irritate the stomach, this is known as irritative gastritis.

Vomiting can be divided into four groups, gastrointestinal disorders, hormonal disorders, systemic and other.

Gastrointestinal disorders:

  • Acute metritis: Inflammation of the lining of the uterus in cats post-birth.
  • Cancer: The abnormal and unchecked proliferation of cells.
  • Coccidiosis: Infection with protozoa (single-celled organism) known as coccidia.
  • Feline panleukopenia: Viral infection caused by the parvovirus.
  • Gastritis: Inflammation of the stomach.
  • Gastric ulcer: A stomach ulcer may be due to too much stomach acid, certain medications, certain poisons, parasites and Helicobacter pylori.
  • Hairballs: Balls of hair that are ingested during grooming and later vomited from the stomach.
  • Inflammatory bowel disease: A number of related diseases caused by different types of inflammatory cells invading the intestinal wall.
  • Intestinal obstruction and foreign bodies: Cats aren’t as prone to swallowing miscellaneous objects as dogs are, however, accidental ingestion may occur when playing. Common objects include hair bands, string, sewing thread and cooked bones.
  • Salmonellosis: Bacterial infection caused by salmonella.

Hormonal (endocrine) diseases:

  • Addison’s disease: Deficiency of corticosteroids, due to the destruction of the adrenal cortices.
  • Diabetes: Endocrine disorder caused when the body doesn’t produce enough insulin or the cells are unable to respond to insulin, starving the cells of glucose.
  • Hyperthyroidism: Caused by a hormone-producing benign tumour of the thyroid gland.

Systemic diseases:

  • Kidney disease: This may be chronic or acute. Acute kidney disease can occur if your cat has ingested a toxin. Chronic kidney disease is common in middle-aged to senior cats as a slow and gradual decline in kidney function occurs.
  • Liver disease: There are several causes of liver disease in cats, including hepatic lipidosis which develops when a cat becomes anorexic (stops eating), the body begins to break down fat to use for energy which is sent to the liver, which can overwhelm the liver, ingestion of toxins, liver inflammation, tumours and portosystemic shunt, which is a congenital disorder (present at birth). A portosystemic shunt is seen most often in cats under 12 months of age.
  • Pancreatitis: Inflammation of the pancreas which may be due to infection, obesity, high-fat diet and trauma.


  • Foreign body: that has become lodged in the stomach or intestines.
  • Certain medications: NSAIDs and antimicrobials.
  • Heatstroke: A life-threatening condition where the body overheats due to prolonged exposure to heat.
  • Motion sickness.
  • Poisoning.
  • Ruptured bladder: Usually caused by trauma or urinary blockage.
  • Worms: Parasitic worms, most often roundworms, although cats can occasionally vomit a tapeworm.

Should I take my cat to the veterinarian?

An isolated incident of vomiting where the cat shows no other signs of illness is not uncommon and generally doesn’t necessitate a trip to the vet. If the vomiting continues beyond 24 hours, if the cat is under 12 months or if you notice other symptoms along with the vomiting, then a trip to the veterinarian is necessary.

You should seek veterinary attention if any of the following symptoms occur:

  • Repeated vomiting
  • Diarrhea (read our article about vomiting and diarrhea in cats)
  • Foul-smelling vomit
  • Lethargy
  • If you suspect your cat has ingested a poison or toxin.
  • Blood in the vomit
  • Listlessness
  • Bloated or painful abdomen
  • Drooling


If possible, when you take your cat to the veterinarian, bring along a sample of the vomit, this will assist the vet to determine the underlying cause of the vomiting.

Your veterinarian will perform a complete physical examination of your cat and obtain a medical history, which will include:

  • When does the cat vomit, immediately after a meal or not?
  • Does the vomiting happen at a certain time or day or after a particular incident (such as a trip in the car)?
  • What medications (if any) is the cat taking?
  • How often does the cat vomit?
  • Is the cat on any medication?
  • What does the vomit look like (frothy, bloody, bile, undigested food)?
  • Is the cat’s appetite normal?
  • Is the cat drinking more or less than usual?
  • Does the cat have diarrhea?
  • Has the cat had access to any poisons (including plants)
  • Is the vomiting acute or chronic?

Types of vomiting

The type of vomiting can help the veterinarian narrow down a possible cause.

Acute vomiting

(sudden onset vomiting with no recent vomiting episodes)
  • Consumption of food that has spoiled
  • Ingestion of a non-food item, such as grass or hairballs,
  • Salmonellosis
  • Pancreatitis
  • Food intolerance
  • Heatstroke
  • Sudden changes in diet
  • Poisoning
  • Gastrointestinal blockage
Chronic vomiting

(vomiting lasting longer than two weeks)
  • Diabetes
  • Kidney disease
  • Hyperthyroidism
  • Liver disease
  • Tumours
  • Food intolerance


Sporadic vomiting

(vomiting not related to eating which comes and goes)
  • Kidney disease
  • Liver disease
  • Heavy worm infestation
  • Diabetes
  • Gastritis


Projectile vomiting

(forceful ejection of vomit which travels a considerable distance)
  • Intestinal blockage
  • Tumour


Vomiting clear fluids
  • Intestinal blockage
  • Prolonged vomiting where all that remains is liquid


Vomiting blood
  • Foreign body
  • Tumours
  • Ulcers
  • Coagulation disorders
  • Ingestion of toxins


Vomiting undigested food:
  • Megaesophagus
  • Eating too fast
  • Playing too soon after eating
  • Food allergy/intolerance


Fecal vomiting

  • Intestinal obstruction
Vomiting brown liquid
  • Bile
  • Eating something brown coloured such as chocolate (which is
  • Bleeding somewhere in the gastrointestinal tract
Vomiting yellow or green fluid (bile)


  • The cat has an empty stomach and all that is left is water and
    gastric juices
  • Pancreatitis
  • Gastritis
Motion sickness
  • Vomiting only occurs when the cat is travelling
Vomiting worms
  • Long, thin, white, spaghetti-like worms in the vomit are a sign
    of roundworm infestation. From time to time a cat may also vomit up
    a tapeworm, which is long, white/cream with a ribbon-like appearance
    and segmented.

Diagnostic workup:

  • Baseline tests: Biochemical profile, complete blood count, and urinalysis to evaluate organ function, check dehydration and look for signs of infection.
  • Endoscopy: A medical procedure to evaluate inside the body using an endoscope, an instrument composed of a thin tube with an eyepiece at one end and a light and camera at the other end. The endoscope is used for direct visual examination of the gastrointestinal tract to look for stomach ulcers, tumours, inflammation or gastrointestinal blockage.
  • Fecal smear or fecal flotation: A sample of the cat’s feces is checked for the presence of parasites.
  • Total T4: To evaluate for hyperthyroidism.
  • FeLV/FIV and heartworm tests: Blood tests to look for heartworm antigen or antibodies to FeLV, FIV and heartworm.
  • Radiographs or ultrasound: To check for gastrointestinal obstruction, cancer, and evaluate organ size.
  • Coagulation profiles: A series of blood tests to measure the body’s ability to form a blood clot. Typical tests include aPTT, INR, fibrinogen and platelets.


The goal of treatment is to find and address the underlying cause as well as provide supportive care.

The type and severity of clinical signs will determine if the cat is hospitalised or treated as an out-patient. A cat who is otherwise bright, alert and responsive, still eating and has no accompanying symptoms may only require home care.

Supportive care:

  • Intravenous or subcutaneous fluids to treat dehydration and reverse electrolyte imbalances.
  • Fast the cat for 6-12 hours and then feed a bland and easily digested diet to rest the gastrointestinal tract. If the cat is not eating, it will be necessary to use a feeding tube to provide nutrition until the cat is well enough to eat.
  • Anti-emetic medications such as chlorpromazine (Thorazine), ondansetron (Zofran) and dolasetron (Anzemet).

Specific treatment:

  • Anti-parasitic medications for internal parasites.
  • Antibiotics to treat bacterial infection.
  • Surgery to remove a foreign object, tumours and repair a twisted bowel or ruptured bladder.
  • Dietary and nutraceutical therapy for inflammatory bowel disease, diabetes, kidney and liver disease.
  • Low iodine diet, surgery (thyroidectomy) or radioactive iodine treatment for cats with hyperthyroidism.
  • Gastric decontamination, activated charcoal and specific antidotes for cats who have ingested poison.
  • Supportive care for cats with viral infections.
  • Lifelong administration of the deficient adrenal hormones (corticosteroid and mineralocorticoid) to manage Addison’s disease.
  • Analgesics as well as anti-nausea medications to treat pancreatitis as well as address the underlying cause.
  • Prescription hairball diet or gastric lubricants such as veterinary grade petroleum jelly to treat hairballs.
  • It is not possible to kill coccidia, but medications can be given which inhibit coccidial reproduction. These include antibiotics or antiprotozoal drugs such as Tylosin, Trimethoprim-sulfa, Ponazuril or Toltrazuril.


  • Julia Wilson, 'Cat World' Founder

    Julia Wilson is the founder of Cat-World, and has researched and written over 1,000 articles about cats. She is a cat expert with over 20 years of experience writing about a wide range of cat topics, with a special interest in cat health, welfare and preventative care. Julia lives in Sydney with her family, four cats and two dogs. Full author bio

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