Why Is My Cat Throwing Up Undigested Food Hours After Eating?


It can be concerning when a cat throws up undigested food, especially if it happens frequently. This article will explore the common causes of cats vomiting undigested food hours after eating, how it can be diagnosed, potential treatments, and ways to prevent it from happening.

The main sections covered include an overview of the most common reasons a cat may vomit undigested food, including eating too quickly, food sensitivities, infections, blockages, and other issues. Diagnostic steps a vet may take are outlined, along with possible treatments depending on the underlying cause. Finally, tips are provided on how to modify a cat’s eating habits and environment to help prevent vomiting of undigested food.

Common Causes

There are several potential reasons why a cat may vomit undigested food hours after eating. Some of the most common causes include:

Eating Too Fast

Cats are known to eat their food very quickly. If a cat eats too fast, this can lead to regurgitation of undigested food. The food doesn’t get properly processed and mixed with digestive enzymes before being vomited back up. This is one of the most common reasons behind a cat throwing up undigested food long after their meal.

Food Sensitivities

Some cats may have sensitivities or intolerances to certain ingredients in their food. Common triggers include corn, wheat, soy, dairy, and fish. If a cat has a sensitivity, their stomach will have trouble properly digesting the food, which can lead to vomiting hours later. Switching to a limited ingredient cat food can help determine if a food allergy is the culprit.


Gastrointestinal infections from parasites, viruses, or bacteria can also cause a cat to vomit undigested food. Infections irritate the stomach lining and affect the digestive process. Some common infections include tritrichomonas foetus, feline panleukopenia virus, and helicobacter pylori bacteria.


Obstructions or blockages in the gastrointestinal tract may prevent food from being properly digested. Things like hairballs, foreign objects, or even tumors can cause a blockage that leads to vomiting. Blockages are serious and require veterinary care.

Eating Too Fast

One of the most common reasons a cat may throw up undigested food hours after eating is that they ate their meal too quickly. When cats eat too fast, they may swallow large chunks of food that haven’t been properly chewed and digested. Their stomach is then unable to break down the food properly before pushing it further along the digestive tract, leading to vomiting.

Cats that bolt down their food are at risk of regurgitation, which is when undigested food comes back up from the esophagus rather than the stomach. This can happen minutes to hours after a meal. Some signs your cat is eating too fast include audible gulping, food falling out of their mouth as they eat, and leaving food uneaten in the bowl.

There are a few things you can do to slow your cat’s eating to prevent vomiting:

  • Feed smaller, more frequent meals throughout the day rather than one or two large meals.
  • Use a puzzle feeder or ball that makes your cat work for their food.
  • Place large rocks or a small amount of water in the food bowl to make your cat eat around them.
  • Purchase a bowl with built-in obstacles, mazes, or raised sections.
  • Consider switching to wet food, which takes longer to eat.

With a few simple changes, you can help prevent your cat from eating too quickly and vomiting up undigested food later on.

Food Sensitivities

Cats can have food allergies or intolerances that lead to vomiting undigested food. Common trigger ingredients include beef, dairy products, chicken, fish, wheat, and corn. When a cat eats something their body views as a foreign invader, it triggers an immune response resulting in inflammation of the stomach and intestines. This can lead to vomiting and diarrhea. Food intolerances are different from true allergies in that they do not involve the immune system. However, they can cause similar gastric upset and vomiting in cats. It’s important to monitor your cat’s diet and watch for signs of sensitivities when introducing new foods.


Infections in the digestive tract can cause a cat to vomit undigested food. Some common infections include:

Pancreatitis – Inflammation of the pancreas, which can be caused by a high-fat diet, trauma, infections, or certain medications. Symptoms include vomiting, abdominal pain, diarrhea, loss of appetite, and lethargy.

Inflammatory bowel disease – Chronic inflammation of the intestinal tract, potentially caused by an abnormal immune response. Symptoms include chronic vomiting, diarrhea, and weight loss.

Intestinal parasites – Worms or protozoa that infect the gastrointestinal tract. Symptoms may include vomiting, diarrhea, weight loss, and a pot-bellied appearance.

Bacterial infections – Bacteria such as Salmonella or Campylobacter can infect the intestines, often from contaminated food or water. Symptoms include vomiting, diarrhea, fever, and abdominal pain.

Viral infections – Feline panleukopenia virus and feline coronavirus are viral infections that can cause gastroenteritis. Symptoms include vomiting, diarrhea, fever, and lethargy.

Treatment involves identifying and treating the underlying infection with antibiotics, anti-inflammatories, or other medications. In some cases, supportive care like fluid therapy may be needed.


One common cause of a cat vomiting undigested food hours after eating is a blockage or obstruction in the gastrointestinal tract [1]. This prevents the food from passing through the digestive system normally. Cats can develop blockages from swallowing foreign objects like hairballs, string, plastic, bones, rocks, and other inedible items [2].

As food tries to pass the obstruction, it causes the intestines to contract abnormally, leading to nausea and vomiting. The vomit contains food the cat ate many hours earlier that was held up by the blockage. In some cases, the obstruction can be severe enough to cut off blood flow and damage the intestinal wall. This is a life-threatening emergency requiring immediate veterinary care.

In addition to vomiting, other signs of an intestinal blockage include lack of appetite, diarrhea, lethargy, and abdominal pain. Owners may also notice their cat acting anxious or crying when attempting to defecate if the blockage affects the lower intestines [3]. Diagnosis involves feeling the abdomen for obstructions during a physical exam and imaging tests like X-rays or ultrasound.

Treatment depends on the location and severity of the blockage. In many cases, surgery is needed to remove the obstruction and may involve cutting out damaged sections of intestine. After surgery, the cat will be hospitalized for several days to recover. Owners can help prevent blockages by keeping string, rubber bands, plastic, and other hazardous items out of reach.

Other Causes

Kidney disease, cancer, stomach ulcers, liver issues, and the ingestion of toxins or foreign bodies can also sometimes cause cats to vomit up undigested food hours after eating, but these are less common causes (Source 1, Source 2). If your cat is exhibiting other symptoms like lethargy, weight loss, increased thirst/urination, or blood in the vomit, you should have your vet run tests to check for underlying conditions. An x-ray or ultrasound may be needed to identify obstructions. If the cause is determined to be something serious like cancer, appropriate treatment will be needed.


To diagnose the underlying cause of a cat vomiting undigested food, vets will typically start with a full physical exam, looking for any abnormalities or signs of illness. They may palpate the abdomen to check for masses, pain, or enlarged organs. Vets will also ask about the cat’s diet, eating habits, activity level, and any other symptoms like diarrhea or lethargy.

If the cause isn’t obvious from the exam, the vet may recommend bloodwork to check for issues like pancreatitis, kidney disease, diabetes or hyperthyroidism. Bloodwork provides a broad overview of organ function and health. The vet may also recommend imaging tests like X-rays or an ultrasound to look for foreign objects, tumors, inflamed intestines, or other issues that could cause vomiting.

In some cases, the vet may collect a fecal sample to test for parasites like giardia or worms. They may also recommend an endoscopy to get a visual examination of the stomach and upper intestines. Biopsies or fluid samples might be taken during an endoscopy to check for cancer or infection.

Once diagnostic testing is complete, the vet will analyze all the results to pinpoint the underlying cause. From there, they can recommend the appropriate treatment plan to stop the cat from vomiting undigested food and address any related health issues.


The treatment for a cat throwing up undigested food will depend on the underlying cause. Here are some common treatments:

For eating too fast – Feed smaller, more frequent meals in a maze bowl or puzzle feeder to slow down eating.

For food sensitivities – Switch to a novel protein or hypoallergenic diet recommended by your vet.

For infections – Antibiotics or anti-parasitic medications prescribed by a vet.

For blockages – Surgery may be needed to remove obstructions. IV fluids and hospitalization may help manage symptoms.

For other causes like cancer – Treatment will depend on the specific illness but may include medications, chemotherapy, radiation therapy, or surgery.

In all cases, be sure to follow your veterinarian’s treatment recommendations. Temporary fasting, anti-nausea medicines, IV fluids, and supportive care may also be prescribed. The key is identifying and treating the underlying cause of the vomiting.


There are several things you can do to help prevent your cat from throwing up undigested food:

  • Feed smaller, more frequent meals – Large meals can overwhelm your cat’s stomach and lead to vomiting. Break meals into smaller portions 3-4 times a day.
  • Slow down fast eaters – Use puzzle feeders or ball feeders to make your cat eat more slowly. This gives the stomach time to digest.
  • Avoid food triggers – If your vet determines your cat has a food allergy or sensitivity, avoid those ingredients.
  • Treat underlying conditions – Follow your vet’s treatment plan for any infections, parasites, etc. causing vomiting.
  • Don’t exercise right after meals – Allow 1-2 hours for digestion before playtime.
  • Provide stress relief – Reduce stressors that may contribute to vomiting like new pets, litter issues, etc.
  • Don’t feed right before travel – Feed at least 4 hours before a car ride to prevent motion sickness vomiting.

Making adjustments to your cat’s diet and environment can go a long way in preventing vomit episodes. But if vomiting persists, always consult your veterinarian.

Scroll to Top