My cat is vomiting: when to wait and when to rush
"Cats vomit, it is normal" is one of the phrases that delays the most diagnoses. A single vomit in a cat that keeps eating and playing is no cause for alarm. Frequent vomiting, even if the cat seems fine, does deserve attention, and some cases are a same-day emergency.
Vomiting, regurgitating or coughing
First of all, it helps to know what you are seeing. Vomiting is active: the cat crouches, contracts the belly several times, makes a retching noise and brings up digested food, liquid or foam. Regurgitation is passive: the food comes out whole, without effort, sometimes right after eating, typical of a cat that gulps or of oesophageal problems. And coughing, especially the asthma cough, looks a lot like an attempt to vomit with nothing coming out. Each points to different causes, so look carefully and, if you can, film it: a ten-second video tells the vet more than any description.
It is not normal for a cat to vomit often
For years it was accepted that a cat might vomit several times a month. Feline medicine guidelines and specialists insist on the opposite: a healthy cat should not vomit frequently, and chronic vomiting, even if it is "only" once or twice a week and the cat eats well, deserves investigation. In adult and older cats, behind the vomiting everyone normalises there are often chronic enteropathies, low-grade intestinal lymphoma, hyperthyroidism, kidney disease or pancreas and liver problems. Many of these treat well if caught early, and go unnoticed for years if blamed on hair.
The most common mild causes
Eating too fast, especially in multi-cat homes where they compete at the bowl, or eating a lot after many hours without food. A change of food that is too sudden. Nibbling plants or grass. The odd hairball. In all these cases the cat vomits once or twice, settles down, still has an appetite and in a few hours is back to normal. If they bring up their food whole right after eating, try smaller, more frequent meals, a slow feeder or a flat plate, and feed cats separately if there is competition.
The causes that cannot wait
String is the classic feline danger: a cat that swallows sewing thread, gift ribbon, dental floss or the elastic from a toy can develop a linear foreign body, where the intestine bunches up along the thread like a curtain and can perforate. Never pull on a thread sticking out of the mouth or the bottom: leave it and go to the vet. Poisonings are also emergencies, and in cats the most serious are lilies (any part, including pollen or the water in the vase, causes kidney failure), paracetamol, dog spot-on treatments containing permethrin, antifreeze and some cleaning products. And pancreatitis, a foreign body blockage, diabetic ketoacidosis and decompensated kidney disease often present with vomiting.
Emergency signs
See the vet the same day if they vomit several times in a few hours, if they cannot keep even water down, if there is blood (red or like coffee grounds), if they retch repeatedly without bringing anything up, if the belly is tense or painful to touch, if they are flat, hiding or weak, if you suspect they have swallowed thread, a plant or a toxin, or if they have also gone more than a day without eating. In kittens and in older cats or cats with chronic conditions such as diabetes or kidney disease, the margin is even smaller. And if they also breathe with the mouth open or struggle to breathe, do not wait a minute.
What to do at home after a single vomit
If they have vomited once and are otherwise fine, take the food away for a few hours, no more, to rest the stomach, and leave a small amount of water available. Then offer a small portion of their usual food or a bland wet food, split into several meals through the day. Unlike dogs, cats should not be kept without food for long: a cat that goes a day or two without eating, especially if overweight, can develop hepatic lipidosis, a serious liver disease. If they vomit again or will not eat over the next few hours, call the vet.
What you must never give them
No human medicines. Paracetamol is deadly to cats even in tiny amounts, because their liver cannot break it down: it destroys red blood cells and the liver within hours. Ibuprofen, aspirin and other human anti-inflammatories cause ulcers and kidney failure. Household antacids, anti-sickness medicines and stomach protectors are no good either: some are dangerous and all of them can mask a serious cause. Do not try to make them vomit with salt water or hydrogen peroxide; in cats it does not work well and can cause injury. If you suspect poisoning, call your vet or an emergency clinic and take the packaging with you.
What the vet will do
First a full examination: feeling the belly for pain, gas, lumps or a thickened loop of intestine, looking under the tongue (where string often gets caught), assessing hydration, temperature and gum colour. Depending on the case, they will request blood tests with kidney and liver function, glucose and, in cats over seven or eight, thyroid hormone; abdominal X-rays or ultrasound to look for foreign bodies or thickening of the intestine; and in chronic vomiting, sometimes biopsies. Treatment ranges from veterinary anti-sickness drugs and fluids to surgery if there is a blockage.
What it can cost
As a guide in Spain in 2026: a normal consultation, 40 to 60 €; an out-of-hours emergency, 70 to 150 € for the visit alone; full blood tests, 80 to 160 €; abdominal ultrasound, 70 to 150 €; and hospitalisation with fluid therapy, 80 to 200 € a day depending on the clinic and the city. Surgery for a foreign body or linear obstruction usually runs from 800 to 2,000 € with hospitalisation. Intestinal biopsies, 400 to 1,200 €. Pet insurance or a small savings fund makes all the difference in these cases.
What to note down before you go
How many times they have vomited and since when, what it looked like (undigested food, digested food, yellow liquid, white foam, hair, blood), whether it happens right after eating or at other times, whether they eat and drink normally, what their faeces are like and when they last passed one, whether they have lost weight, whether they have access to plants, thread, toys with strings or cleaning products, and whether anything has changed in their diet or at home. Take a photo of the vomit before you clean it up. If the vomiting is chronic, a short diary over two or three weeks with dates and appearance is gold for the vet.
A single vomit in a cat that keeps eating and is lively is no cause for alarm, but vomiting often is not normal in a cat, even if it is hairballs. String, lilies, paracetamol and dog spot-ons are emergencies, and never leave a cat more than a day without eating: the liver does not forgive it.
Educational content from Michipedia, translated from the Spanish original. It does not replace the advice of a vet or a feline behaviour specialist. Every cat is an individual.