Vomiting or regurgitation? They are not the same
This is the first thing your vet will ask, so it pays to know. Vomiting is active: the cat retches, the abdomen contracts, and partially digested material comes up from the stomach or small intestine. Regurgitation is passive — undigested food appears without warning, often right after eating too fast (PetMD).
Coughing gets mislabeled as vomiting too. The difference: vomiting involves the abdomen; a cough involves the neck and airway. If you're not sure which one you're seeing, film it — PetMD explicitly recommends showing your vet a video.
What the vomit tells you
Color and contents narrow the cause list. They never replace the exam, but they give your vet a head start (PetMD):
- Yellow or green — stomach acid or bile, typical when the stomach is empty or the cat hasn't eaten due to illness.
- Blood — ulcers or irritation of the stomach or esophagus from repeated vomiting. Contact your vet.
- White foam — the stomach or small intestine is inflamed.
- Clear liquid — stomach fluid or water the cat recently drank.
- Worms — roundworms can appear in vomit. Contact your vet for treatment.
- Hairball — common, especially in long-haired cats or over-groomers.
- Black or dark brown — digested blood, seen with ulcers, foreign bodies or intestinal inflammation. Contact your vet right away.
- Mucus — more consistent with regurgitation than vomiting.
When to call — and when to run
PetMD's thresholds are concrete, so use them:
- Call the vet if your cat vomits more than two to three times in a row, vomits alongside diarrhea or appetite loss, vomits a worm, or can't keep food or water down.
- Go now if the vomit contains blood or black material — or if your cat has a diagnosed chronic illness. Repeated vomiting in a cat with diabetes, kidney disease or hyperthyroidism is an emergency; they dehydrate quickly, and early intervention matters (PetMD).
- Call poison control if toxin ingestion is even suspected, and bring the packaging.
- Kittens and seniors get a lower bar: small bodies dehydrate fast (PDSA).
What not to do at home
Do not give over-the-counter medications for vomiting unless your veterinarian directs it (PetMD). Do not keep refilling the food bowl to “see if it stays down” — repeated vomiting needs a feeding plan from the vet, not trial and error.
What actually helps: keep water available, note the time of each episode and what came up, photograph it, and write down anything odd your cat might have eaten — string, plants, human medication. At the visit, expect a physical exam checking for abdominal pain and dehydration, then likely bloodwork, urinalysis, a fecal test and possibly X-rays or ultrasound (PetMD).
Mild cases are often treated as outpatients with fluids, supportive care and a bland diet. Severe or dehydrated cats are hospitalized for IV fluids, with anti-nausea medication and treatment aimed at the underlying cause — parasites, kidney disease, thyroid disease and more (PetMD).
Frequently asked questions
How often can a cat vomit before I should worry?
PetMD's line is clear: more than two to three times in a row earns a call, and so does vomiting paired with diarrhea, appetite loss, or inability to keep water down. An isolated episode in a bright, eating cat can be watched (PDSA).
Why does my cat throw up right after eating?
Food coming up passively, without retching, is regurgitation rather than vomiting — often from eating too fast (PetMD). Slowing meals with a puzzle feeder helps, but if it keeps happening, mention it to your vet: regurgitation has its own cause list.
My cat is vomiting black liquid. Is that an emergency?
Yes. Dark or black vomit indicates digested blood and can occur with ulcers, foreign bodies or intestinal inflammation — contact your veterinarian right away (PetMD). The same goes for fresh blood in the vomit.
Do hairballs mean something is wrong?
Occasional hairballs are normal, especially for long-haired cats or heavy groomers (PetMD). But hairballs are also the easiest label to overuse — if vomiting is frequent, or comes with appetite or weight changes, it needs a workup rather than another tube of hairball gel.