Why Does My Cat Keep Throwing Up Whole Food? The Reasons Behind Feline Regurgitation


Cats occasionally vomiting up undigested food is quite common. There are various potential reasons why your cat may be throwing up undigested food right after eating. In some cases, it may be due to minor issues like eating too quickly or changes to their diet. However, frequent vomiting of undigested food can also signal more serious underlying conditions that require veterinary attention.

Some of the main reasons a cat may throw up undigested food include:

  • Eating too fast
  • Food allergies or intolerance
  • Parasites
  • Inflammatory bowel disease
  • Foreign object obstruction
  • Hairballs
  • Side effects of medication

This article explores the various causes behind cats throwing up undigested food, when you should see a vet, how it’s diagnosed, and prevention methods. Understanding why your cat is vomiting can help you address the issue and provide proper care.

Dietary Causes

Eating too quickly is one of the most common dietary causes of cats throwing up undigested food. Cats are known to be fast eaters, and gobbling down food can lead to vomiting soon after the meal. Eating too fast causes air to get trapped in the stomach, which then gets expelled along with the undigested food. Using puzzle feeders or maze bowls that slow down eating can help prevent this issue.

Food intolerances or sensitivities are another potential dietary cause. Some cats may have difficulty properly digesting certain ingredients like dairy, fish, chicken, beef or wheat. An intolerance leads to irritation of the stomach and intestinal tract, resulting in vomiting. If a specific ingredient seems to trigger vomiting, it should be eliminated from the diet.

Spoiled, contaminated or rancid food is also a common reason for undigested vomiting. Bacteria and molds that grow in outdated or improperly stored cat food can irritation in the digestive system. Always check expiration dates, follow storage instructions, and inspect wet food cans for bulges or rust that may indicate spoilage.

Sudden changes in diet can also lead to indigestion and vomiting. Transitioning to a new food too quickly doesn’t give the stomach time to adjust. Make dietary changes gradually over 5-7 days when switching foods.

Overeating or having too large of a meal is another potential dietary cause. Eating too much food distends the stomach, and the excess may get ejected through vomiting. Feed cats smaller, more frequent meals and avoid free-feeding throughout the day.

Diseases and Disorders

There are several diseases and disorders that can cause a cat to vomit undigested food. Some of the most common include:

Inflammatory bowel disease (IBD) – This refers to a group of chronic gastrointestinal disorders that cause inflammation of the digestive tract. It can lead to vomiting, diarrhea, and weight loss. IBD is often caused by an abnormal immune reaction or food allergies [1].

Pancreatitis – This is inflammation of the pancreas. It’s often triggered by a high-fat diet. Symptoms include vomiting, diarrhea, decreased appetite, lethargy, and abdominal pain [2].

Hyperthyroidism – This is characterized by overproduction of thyroid hormones. It’s a common disease in older cats. Vomiting, diarrhea, weight loss, increased appetite, and hyperactivity are some typical signs [3].

Other possible diseases and disorders include cancer, kidney disease, liver disease, infections, parasites, food allergies, and gastrointestinal obstructions.

Foreign Objects

Cats often ingest foreign objects like string, thread, plastic, rubber bands, paper, tinsel, and fabric. According to VCA Animal Hospitals (source), cats may swallow these objects out of curiosity or while grooming and playing. Many foreign bodies can pass through the digestive system without issue. However, larger, longer, or sharp objects may get stuck in the esophagus, stomach or intestines, potentially causing an obstruction or tearing.

Symptoms of a gastrointestinal obstruction from a foreign body include vomiting, especially vomiting undigested food, gagging, loss of appetite, lethargy and dehydration. According to PetCo (source), cats may vomit repeatedly as their body tries to expel the foreign object. Vomiting may become more frequent and contain bile or blood. A foreign body obstruction is a medical emergency requiring immediate veterinary care.

To help prevent foreign body ingestion, keep plastic bags, string, thread and other small objects out of reach. Provide appropriate cat toys and scratching posts so your cat is less likely to play with unsafe objects. Regularly inspect cat toys and replace any that are damaged or could break into pieces. Keep lids on trash cans. Monitor your cat when playing with toys to ensure they are not destroying and ingesting them. Contact your vet if your cat displays symptoms of a possible foreign body obstruction.


One common cause of cats vomiting undigested food is hairballs. Cats groom themselves frequently, swallowing loose hair in the process. Usually, most of this hair will pass through the digestive tract and be eliminated in the stool. However, some of the hair can accumulate into hairballs in the stomach and intestinal tract, causing irritation, obstruction, and vomiting. As the cat’s stomach contracts to try to pass the hairball, this can force partially digested food back up as well, leading to vomiting of undigested food.

Hairballs tend to be more prevalent in long-haired cat breeds who groom more aggressively. But any cat can develop hairballs. Symptoms include gagging, retching, and coughing up hairballs, as well as intermittent vomiting of undigested food. Treatment involves grooming to remove loose hair, hairball remedies and lubricants, increased hydration, and sometimes medications to improve gastric motility. Preventing excessive self-grooming and ingestion of hair is key to reducing hairballs.

According to PetMD, “Any time a cat is throwing up undigested food regularly, hairballs should be suspected as the cause.”[1] The Spruce Pets also notes that hairballs often contribute to cats throwing up undigested food shortly after eating.[2] So when a cat is vomiting up undigested food, examining their hairball status and targeting hair ingestion is an important part of solving the problem.


Stress can have a major impact on a cat’s digestive system and lead to vomiting of undigested food. When a cat experiences stress or anxiety, their body releases adrenaline and cortisol. These hormones can increase stomach acid production and disrupt the normal motility of the gastrointestinal tract (Cats.com).

The excess stomach acid coupled with slowed digestion can cause irritation of the stomach lining and esophagus. Food may not be properly broken down and can cause regurgitation of whole, undigested pieces. Stress can also cause vomiting if the stomach and intestines start contracting spasmodically.

Common stressors like adding a new pet to the home, construction noise, travel, or a change in routine can all prompt anxious behaviors in cats. Cats are creatures of habit and any disruption can be stressful. Recognizing and minimizing stress triggers is key to preventing digestive upset. Paying attention to your cat’s body language and providing calming solutions like pheromone diffusers can also help (Untamed Cat Food). If vomiting due to stress becomes frequent, consult your veterinarian for advice.

When to See the Vet

If your cat is vomiting undigested food, it’s important to monitor the situation carefully. In some cases, a vet visit is warranted. Here are some guidelines on when vomiting should prompt a trip to the veterinarian:

Vomiting lasts more than 24 hours – If the vomiting persists beyond a day, dehydration becomes a serious risk. It’s best to have your cat seen by a vet.

Vomiting is projectile – Forceful, projectile vomiting can indicate a blockage or other urgent issue requiring veterinary care.

Presence of blood – Any sign of blood in the vomit warrants an immediate vet visit, as it may signal internal injury or illness.

Weight loss – If your cat is losing weight along with vomiting, a medical issue may be preventing proper nutrient absorption. See your vet.

Lethargy – If your cat seems exhausted, weak, or depressed along with vomiting, a vet visit is a must.

Difficulty breathing – Labored breathing alongside vomiting is an emergency situation requiring vet attention.

Fever – An elevated body temperature along with vomiting indicates infection or inflammation needing treatment.

Inappetence – If your cat refuses food or water for 12+ hours while vomiting, the cat is at risk of hepatic lipidosis. Seek vet care.

Signs of pain – If your cat seems painful or cries out when vomiting, visit your vet to identify and treat the source.

Young kittens – Kittens under 6 months old who vomit often need veterinary assessment to prevent dehydration.

Whenever in doubt about the cause or severity of vomiting, it’s wise to have your cat examined by a veterinarian. It’s better to be safe than sorry when monitoring your cat’s health.


If a cat is throwing up undigested food frequently or showing concerning symptoms along with the vomiting, a veterinarian will need to run diagnostic tests to determine the underlying cause. Some common diagnostics the vet may perform include:

Blood work – Looking at a complete blood count and blood chemistry can reveal issues like pancreatitis, kidney disease, diabetes, hyperthyroidism, cancer and more. Bloodwork provides an overview of how the major organs are functioning.

Fecal exam – Checking a stool sample for parasites like giardia or worms which can cause digestive upset.

Imaging – X-rays or ultrasound of the abdomen to look for foreign objects, tumors, obstructions, or other issues. Imaging provides visual confirmation of problems.

Endoscopy – Using an endoscope camera to look inside the esophagus, stomach and upper intestines. Endoscopy is helpful for identifying inflammation, ulcers, tumors, foreign objects, etc.

Biopsy – Taking tissue samples of the stomach, intestines or lymph nodes if cancer is suspected and needs diagnosis.

By running diagnostic testing, the veterinarian can narrow down the list of possible causes and determine if the cat requires specific medication, dietary changes, or surgery to treat the vomiting.


The treatment for a cat throwing up undigested food depends on the underlying cause. Some possible treatments include:

If the cause is eating too fast, treatments may include feeding smaller, more frequent meals, getting a slow feeder bowl, or putting large rocks in the regular bowl to slow down eating. For food allergies or intolerances, a vet may prescribe a hypoallergenic diet. If there is an intestinal blockage, surgery may be required to remove the obstruction. In cases of viral infections, antibiotics and anti-nausea medication may help. Hairballs can be treated with hairball remedy pastes or by brushing your cat regularly. Veterinarians may prescribe antiemetic drugs for cats dealing with frequent vomiting. Identifying and addressing the root cause is key to stopping the vomiting of undigested food.


There are several things cat owners can do to help prevent their cat from vomiting undigested food:

  • Feed smaller, more frequent meals – Large meals can overwhelm your cat’s digestive system. Break meals into smaller portions fed more often throughout the day. (1)
  • Slow down eating – Place large rocks or ice cubes in your cat’s bowl to make them eat around them, slowing down intake. Raised bowls also slow eating. (2)
  • Groom regularly to reduce hairballs – Daily brushing helps remove loose hair your cat might ingest. Regular brushing also helps distribute skin oils to help move hairballs through the digestive tract. (3)
  • Reduce stress – Environmental stress can increase vomiting. Make sure your cat has safe zones, proper litter box maintenance, and a consistent routine.
  • Change food gradually – When changing foods, transition slowly over 7-10 days, gradually increasing the new while decreasing the old.

Preventative care, like routine vet checkups and ensuring your cat stays hydrated, can also help reduce instances of vomiting undigested food.

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