A cat that stops eating and starts vomiting is telling you something is wrong. These two symptoms together are one of the most common reasons cats end up at the vet, and the causes range from a simple upset stomach that resolves on its own to serious conditions that need immediate treatment. The key is knowing how to read the situation so you can act at the right speed.
Why These Two Symptoms Go Together
Vomiting and appetite loss are tightly linked in cats. Nausea kills the desire to eat, and whatever is irritating the stomach or intestines typically triggers both responses at once. The most common causes fall into a few categories:
- Food reactions: A sudden diet change, spoiled food, or a sensitivity to an ingredient can cause acute vomiting and food refusal. This is one of the most frequently identified triggers in cats with both acute and chronic vomiting.
- Hairballs: Cats vomit hairballs more than any other domestic animal because of their intense grooming habits. A large hairball moving through the digestive tract can cause nausea and temporary appetite loss.
- Infections: Viral infections like panleukopenia (especially dangerous in unvaccinated cats) and bacterial infections can cause sudden vomiting, lethargy, and complete food refusal.
- Inflammatory bowel disease: Chronic inflammation of the stomach or intestinal lining is one of the most common causes of ongoing vomiting in cats. It develops gradually and often comes with weight loss over weeks or months.
- Kidney disease: When the kidneys can’t filter waste properly, toxins build up in the blood and cause persistent nausea. This is especially common in older cats.
- Liver disease: The liver processes toxins and produces bile. When it’s compromised, cats often vomit and refuse food.
- Overactive thyroid: Hyperthyroidism is common in older cats and frequently causes vomiting alongside increased thirst, weight loss, and restlessness.
- Foreign objects: Cats don’t swallow random objects as often as dogs, but when they do, string and thread are the classic culprits. A linear foreign body can bunch up the intestines and cause severe, rapid symptoms.
Signs That Need Urgent Attention
Not every episode of vomiting is an emergency, but certain patterns should move you to act fast. If your cat is vomiting repeatedly over the course of a few hours, showing lethargy, hiding more than usual, or has diarrhea alongside the vomiting and food refusal, a vet visit shouldn’t wait.
Pay attention to what the vomit looks like. Thick yellow vomit or vomit containing anything unusual (string, fabric, foreign material) points toward a more serious problem. Non-productive retching, where your cat is heaving but nothing comes up, can signal an obstruction and is a genuine emergency.
A sudden change in vomiting frequency matters too. A cat that rarely vomits and is now doing it multiple times in a day is a different situation than an occasional hairball. As a general benchmark, vomiting more than a couple of times per month warrants a veterinary evaluation even if the cat seems otherwise fine.
How to Check for Dehydration at Home
A cat that’s vomiting and not eating loses fluid fast. Dehydration can become dangerous within 24 to 48 hours, so it helps to know how to spot it early.
The gum test is the simplest check. Lift your cat’s lip and touch the gums. They should feel wet and slippery. If they feel dry or sticky (what vets call “tacky”), your cat is losing fluids. Healthy gums are also pink; pale or white gums signal a more serious problem.
You can also do a skin turgor test. Gently pinch and lift the skin over your cat’s shoulders, then let go. In a well-hydrated cat, the skin snaps back into place almost instantly. If it stays “tented” or slowly settles back down, dehydration is already significant. One caveat: older cats naturally have less elastic skin, so this test is less reliable in senior cats. Other signs of dehydration include sunken-looking eyes, weakness, and deepening lethargy.
Poisoning as a Possible Cause
If the vomiting came on suddenly and your cat had access to something it shouldn’t have, poisoning is worth considering. Common culprits include household cleaners (bleach, detergents, disinfectants), antifreeze, paint thinner, and fertilizers. Certain human foods are also toxic to cats, including grapes, raisins, onions, avocados, and anything sweetened with xylitol.
Poisoning symptoms often include drooling, unsteady walking, heavy breathing, and seizures alongside the vomiting. If you suspect your cat ingested something toxic, this is always an emergency. Bring the product packaging or plant with you to the vet if you can.
What to Do in the First 12 to 24 Hours
If your cat vomited once or twice but is still alert, not in obvious pain, and doesn’t show any of the red flags above, you can monitor closely at home for a short window. Remove food for a few hours to let the stomach settle, but keep fresh water available. Cats that are nauseous often avoid their water bowl too, so watch whether they’re drinking at all.
After a few hours of rest, offer a small amount of food. The traditional advice was to prepare boiled chicken breast and white rice, but veterinary nutritionists now advise against this. That combination is deficient in more than 10 essential nutrients cats need, and the calorie content is unpredictable. A better option is a commercial veterinary bland diet, which your vet can recommend or which you can find at most pet stores. These are nutritionally complete and designed specifically for sensitive stomachs.
Offer tiny portions, about a tablespoon at a time, and wait to see if it stays down. If your cat refuses food entirely for more than 24 hours, that alone is reason to call the vet. Cats are uniquely vulnerable to a liver condition called hepatic lipidosis that can develop when they go without eating for even a few days. This is especially true for overweight cats.
What Happens at the Vet
Your vet will likely start with a physical exam, feeling your cat’s abdomen for pain, masses, or thickened intestines. Blood work is usually the next step, checking kidney and liver function, thyroid levels in older cats, and signs of infection or inflammation. If the vet suspects an obstruction or something structural, X-rays or an ultrasound can reveal foreign objects, intestinal blockages, or organ abnormalities.
For cats with chronic vomiting (ongoing for weeks or longer), the workup may eventually include a food trial to rule out dietary sensitivities, or biopsies of the intestinal lining to check for inflammatory bowel disease.
Treatment depends entirely on the cause. A cat with a simple stomach upset might go home the same day with anti-nausea medication and a dietary plan. A cat with an intestinal obstruction from swallowed string will need surgery. Kidney disease, liver problems, and hyperthyroidism all have their own long-term management plans, but they’re all treatable, especially when caught before they’ve progressed too far.
Patterns Worth Tracking
If your cat has recurring episodes of vomiting and appetite loss, keeping a log helps your vet enormously. Note when the vomiting happens (morning, after meals, overnight), what the vomit looks like (undigested food, bile, foam, hairball), and any changes in litter box habits. Also track what food your cat ate in the 24 hours before the episode. Patterns often emerge that point directly to a food sensitivity, a hairball problem that needs management, or a chronic condition that’s been building slowly.