By Dial A Vet Veterinary Team
A cat with vomiting and diarrhoea at the same time is losing fluid from both ends, and cats do not have much reserve. Many cases are short-lived upsets from a food change, hunting, or a hairball, and settle within a day. But the combination can also signal infections such as panleukopenia, poisoning (including lilies), a swallowed string, pancreatitis, or flare-ups of chronic disease. Cats also have a particular risk that dogs do not: a cat that stops eating for more than a day or two can develop a serious liver condition called hepatic lipidosis. That is why vets take vomiting and diarrhoea in cats seriously, especially in kittens and older cats.
Key takeaways
- Vomiting and diarrhoea are symptoms with many possible causes, from mild dietary upset to emergencies.
- Cats should not be fasted at home for long periods. Not eating for 24 hours or more needs veterinary advice.
- Kittens, seniors, and cats with kidney disease, diabetes, or thyroid disease become unwell faster.
- Lily exposure, string ingestion, and repeated vomiting are emergencies.
- Recurring episodes over weeks need investigation, even if each one seems mild.
Common causes
- Dietary upset. A sudden food change, rich treats, milk, scavenging, or eating prey.
- Hairballs. More often vomiting than diarrhoea, but common in long-haired cats.
- Parasites. Worms, Giardia, coccidia, and Tritrichomonas, particularly in young or shelter cats.
- Infections. Panleukopenia (feline enteritis) is a severe, vaccine-preventable virus. See panleukopenia in cats.
- Toxins. Lilies, some houseplants, human medicines, and household chemicals.
- Foreign bodies. String, thread, ribbon, and hair ties are dangerous.
- Pancreatitis. See pancreatitis in cats.
- Chronic disease. Inflammatory bowel disease, intestinal lymphoma, hyperthyroidism, kidney disease, and liver disease. See frequent vomiting in cats.
Signs to watch for
- How often vomiting and diarrhoea happen, and what they look like
- Blood in the vomit or stool, or black, tarry stools
- Reduced appetite or refusal to eat
- Lethargy or hiding
- Dehydration: sticky gums, sunken eyes, or skin that stays tented when gently lifted
- A tense or painful belly
- Changes in drinking or urination
When to see a vet
Go to an emergency vet now if your cat:
- Has vomited several times in a few hours or cannot keep water down
- Has blood in the vomit or stool, or very dark, tarry stools
- May have been exposed to lilies (any part, including pollen and vase water) or medicines
- Has string or thread visible from the mouth or bottom (do not pull it)
- Is weak, collapsed, or very flat
- Is a kitten, or is unvaccinated, with both vomiting and diarrhoea
- Is a male cat straining in the litter tray with little or no urine
Book a same-day appointment if: your cat has not eaten for 24 hours, signs have lasted more than a day, or your cat has an existing condition such as kidney disease, diabetes, or hyperthyroidism.
Reasonable to monitor closely for up to a day, with a call to your clinic: an adult cat that has vomited once or twice, or had one or two soft stools, and is otherwise bright, eating, and drinking.
How vets diagnose and treat it
Your vet will check hydration, temperature, belly comfort, heart rate, and the mouth (including under the tongue for string). Depending on the history and findings, tests may include blood and urine tests, a faecal test, X-rays, or ultrasound. For recurring problems, thyroid levels, B12, and further gut investigations may be recommended.
Treatment depends on the cause and severity. It may involve fluid therapy, anti-nausea medication, appetite support, a digestible diet, parasite treatment, and in some cases hospital care or surgery. For cats that will not eat, vets may use appetite stimulants or a temporary feeding tube to protect the liver. Your vet will choose treatments safe for your cat.
Caring for your cat at home
- Keep fresh water available. Some cats prefer running water or a wide bowl.
- Offer small, frequent meals of a bland or vet-recommended gastrointestinal diet.
- Do not withhold food for long periods unless your vet advises it.
- Keep the litter tray clean and note stool quality.
- Separate from other cats if an infection is possible.
- Never give human medicines. Paracetamol, ibuprofen, and many anti-diarrhoea products are dangerous for cats.
Prevention
- Change diets gradually over about a week.
- Keep lilies out of the house and garden entirely.
- Store string, sewing thread, ribbon, and hair ties out of reach.
- Keep vaccinations and worming current.
- Arrange regular checks for older cats to catch kidney or thyroid disease early.
FAQ
How long can a cat go without eating?
Cats should not go more than about 24 hours without eating before you speak to a vet. Longer periods risk hepatic lipidosis, especially in overweight cats.
Can I give my cat chicken and rice?
Short-term plain cooked chicken can help some cats, but cats need balanced nutrition. Ask your vet about a suitable bland or gastrointestinal diet.
Is vomiting and diarrhoea contagious to other cats?
Some causes, such as panleukopenia and certain parasites, are. Keep sick cats separate and wash hands.
Could it be something my cat caught hunting?
Yes. Hunting cats are exposed to more parasites and spoiled prey. Mention hunting to your vet.
Talk with a vet
If your cat has vomiting and diarrhoea and you are not sure whether it can wait, our vets can help you decide by video. Photos of vomit and stool are useful. Book a consult at dialavet.com. Lily exposure, repeated vomiting, blood, or a weak cat needs an emergency clinic straight away.
References
- Cornell Feline Health Center. Vomiting and diarrhea in cats.
- Merck Veterinary Manual. Feline Panleukopenia and Hepatic Lipidosis in cats.
- ASPCA Animal Poison Control. Lilies and cats.
- International Cat Care. Gastrointestinal problems in cats.
Disclaimer: Educational only. This page does not replace an examination or advice from your own veterinarian. If your cat has repeated vomiting, blood, or possible lily exposure, contact a veterinary hospital immediately.