Cat Vomiting – Causes and Treatment of Vomiting in Cats

Causes of cat vomiting      When to see a veterinarian      How is the cause of vomiting diagnosed?      How is vomiting treated?

Vomiting in cats

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 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.

Causes of vomiting in cats:

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

Eating food too fast is another common cause of vomiting.  You may notice your cat race to eat his food only to vomits it back up thirty seconds later, the vomit looks and smells just like cat food.

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.
  • Coccidiosis – Infection with a 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.
  • 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.
  • Salmonella – Bacterial infection caused by salmonella.

Hormonal (endocrine) diseases

  • Addison’s disease – Deficiency of corticosteroids, due to the destruction of the adrenal cortices.
  • Feline 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 – Usually 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.


  • A foreign body such as a cooked bone, cat toy which has become lodged in the stomach or intestines.
  • Certain medications including NSAIDS and antimicrobials.
  • Heat stroke.
  • Morning sickness.
  • Motion sickness.
  • Poisoning.
  • Ruptured bladder – Usually caused by trauma or urinary blockage.
  • Twisted or obstructed bowel.
  • Worms – Parasitic worms, most often roundworms, although cats can occasionally vomit a tapeworm.

When should my cat be taken to a 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 if any of the following symptoms occur:

  • Repeated vomiting
  • Diarrhea
  • 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

How is vomiting diagnosed?

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, including possible exposure to toxins and dietary history (including possible dietary indiscretions) any medications your cat may be on. The type of material vomited, frequency, the age of your cat, and other clinical signs your cat is displaying can all help your veterinarian. He will also need to differentiate between vomiting, regurgitation, and coughing, all of which can be similar.

Being able to assess the vomiting will assist your veterinarian. He may ask about the type of vomiting your cat has been experiencing.

Acute vomiting

  • Consumption of food that has spoiled
  • Ingestion of a non-food item, such as grass or hairballs,
  • Salmonella
  • pancreatitis
  • food intolerance
  • Heat stroke
  • Sudden changes in diet
  • Poisoning
  • Gastrointestinal blockage

Chronic vomiting

  • Diabetes
  • Kidney disease
  • Hyperthyroidism
  • Liver disease
  • Tumours
  • Food intolerance

Sporadic vomiting

This is occasional vomiting that is not related to eating, the cat vomits on and off.

  • Kidney disease
  • Liver disease
  • Heavy worm infestation
  • Diabetes
  • Gastritis

Projectile vomiting

Forceful ejection of vomit which goes a considerable distance.

  • Intestinal blockage
  • Tumour

Vomiting clear fluids

This may be due to an intestinal obstruction or in cases of prolonged vomiting, the stomach contents may have already been vomited and all that remains is liquid.

Vomiting blood (hematemesis)

  • 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 white foam

  • This can be an indication your cat has an empty stomach and all that is left is water and gastric juices.

Vomiting brown liquid

  • Bile
  • Eating something brown coloured such as chocolate (which is toxic)
  • Bleeding somewhere in the gastrointestinal tract

Vomiting bile (yellow/green fluid)

  • The cat has an empty stomach and all that is left is water and gastric juices. Other causes include pancreatitis or 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 tests:

  • Baseline tests including complete blood count, biochemical profile and urinalysis to evaluate organ function, check dehydration and look for signs of infection.
  • Endoscopy to look for stomach ulcers, tumours, inflammation or a gastrointestinal blockage.
  • Fecal examination to check for parasites.
  • Total T4 may be performed on an older cat to evaluate for hyperthyroidism.
  • FeLV/FIV tests.
  • Abdominal X-rays or ultrasound to check for gastrointestinal obstruction, cancer, and organ size.
  • Coagulation profiles to look for clotting abnormalities.
  • Heartworm testing.

Treating vomiting in cats:

Treatment is aimed at finding and treating the underlying cause of the vomiting. In addition, supportive care such as fluids to treat dehydration and correct electrolyte imbalances will be provided.

Other treatments may include:

  • Anti-nausea medication to control the vomiting.
  • Antibiotics to treat a bacterial infection such as salmonella.
  • Medications and supportive care to treat protozoal infections.
  • Addison’s disease requires life-long administration of the deficient corticosteroids.
  • Pancreatitis – Finding and treating the underlying cause (where possible). Painkillers, anti-nausea medication, and supportive care.
  • Surgery to remove any foreign objects your cat may have digested.
  • Surgery to remove tumours and chemotherapy.
  • Hyperthyroidism is usually treated with radioactive iodine which is taken up by the thyroid tumour and destroys it.
  • Liver disease – Supportive care with IV fluids & nutrients, anti-nausea medications (where necessary).
  • Kidney disease is managed with a low protein diet, phosphorus binders, and anti-nausea medication (if necessary).
  • If poisoning is the cause, your veterinarian may pump the stomach, give your cat activated charcoal to absorb some of the toxins, or administer ethanol (for antifreeze poisoning).
  • Supportive care for cats with viral infection while the body fights off the infection.  He may possibly require antibiotics if he develops a secondary bacterial infection.
  • De-worming medications to treat parasitic worms.
  • Eating too fast is an extremely common cause of vomiting in cats and is generally not harmful. Try to feed your cat smaller meals but more frequently.
  • Food allergies or intolerances can be managed by switching to a hypoallergenic diet.