Why Is My Cat Throwing Up Undigested Food?

Has your cat been throwing up undigested food lately? As a feline parent, seeing your furry friend vomit their meals can be worrying. However, cats throwing up undigested food now and then is actually quite common.

While it’s usually not serious, frequent episodes can signal an underlying health issue. Getting to the root cause is key to stopping the vomiting and keeping your cat healthy.

In this comprehensive guide, we’ll explore the top reasons for undigested cat vomit and provide tips to resolve this problem once and for all.

Common Causes of Undigested Vomit in Cats

Many factors can cause your cat to bring up undigested food. Here are some of the most common causes veterinarians see:

Eating Too Fast

Does your cat gobble down their food within minutes? Eating too quickly doesn’t give their stomach enough time to thoroughly digest meals before sending it on to the intestines.

When cats gorge their food, it sits in the stomach undigested until their body forcibly ejects it back up. Underlying issues like stress, competition with other pets, or extreme hunger can trigger speed eating.

Tip: Slow down your cat’s eating pace by placing large rocks or a ball in their bowl so they have to eat around it. Puzzles feeders that make cats “hunt” for food work too.Divide daily portions into 3-4 smaller meals.


Hairballs are another classic cause of undigested vomit. As cats groom themselves, loose hair gets swallowed and mixes with food in the stomach.

It combines into a dense hairball that their body tries to eject through vomiting. Excessive grooming and not enough brushing leads to more hairballs.

Tip: Brush your cat daily to remove loose hair. Give hairball remedying treats or foods to move hair through the digestive tract.

Food Allergies or Intolerances

Just like humans, cats can develop sensitivities to ingredients in their food. Common triggers include beef, dairy, chicken, fish, and wheat gluten.

An allergy or intolerance induces nausea and vomiting since their body sees the food as an invader. It tries to expel the irritant by vomiting up undigested food.

Tip: Trial feeding a hypoallergenic or novel protein diet like duck, kangaroo, or venison to isolate the allergen.


Intestinal parasites like worms and protozoa can also cause tummy troubles and vomit. The parasites irritate the stomach and intestinal lining.

Cats with heavy parasite loads may throw up food before their body can digest it. Worms and protozoa are highly contagious between pets living together.

Tip: Have your vet test a fecal sample and provide deworming medication if parasites are found. Keep cats on monthly preventatives.

Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) involves chronic inflammation of the digestive tract, typically the large and small intestine.

Thickening of the intestinal walls makes it difficult for food to digest and pass normally. This leads to persistent loose stools, vomiting, and weight loss.

Tip: Veterinary prescribed anti-inflammatory medications and specialty diets can help manage IBD. Identifying and eliminating dietary triggers is key.

Foreign Body or Blockage

Cats are infamous for swallowing random non-edible objects that appeal to their senses. String, hair ties, tinsel, yarn, rubber bands — you name it.

If these foreign items get lodged in the esophagus or intestines, they can partially or completely block food from passing. Obstructions cause vomiting after eating.

Tip: Keep tempting objects out of reach and provide safe toys. Lookout for signs of blockages like appetite loss or lethargy. Seek emergency surgery for total blockages.

Rapid Diet Change

Sudden changes to your cat’s diet can upset their digestive system and lead to undigested vomit. Their stomach needs time to adjust to new foods.

Abruptly switching formulas, flavors, or protein sources can overwhelm their digestive enzymes and cause nausea.

Tip: Gradually transition your cat to a new food over 5-7 days by mixing a little more each day. Keep your vet informed about diet changes.

How to Determine The Cause of Undigested Vomiting

Pinpointing what’s causing your cat to throw up undigested food involves a bit of feline detective work. Here are some tips to get to the bottom of it:

  • Take note of any diet or behavior changes preceding the vomiting episodes. Did their appetite or energy levels change? Have their bathroom habits changed? Look for clues that point to potential causes.
  • Examine the vomit. Check if it contains only food or also has hair, foreign material, blood, or unusual color and consistency. This provides insight into the culprit.
  • Make a list of episodes including date, time, what your cat ate beforehand, and appearance of vomit. Look for any patterns around certain foods, schedules, behaviors, etc.
  • Collect a sample of your cat’s vomit and take it with you to the vet appointment. This gives your vet valuable visual clues to possible causes.
  • Have your vet run tests like bloodwork, fecal exam for parasites, x-rays, or endoscopy to check for underlying illness. Diagnostic tests are key for identifying obscure causes of vomiting.

Getting to the bottom of undigested vomiting requires paying close attention to your cat’s habits and health. You also need a vet willing to partner with you to uncover the root cause through testing.

Tips to Stop Your Cat from Throwing Up Undigested Food

Once you get to the bottom of why your cat is throwing up undigested food, take action to resolve the issue:

For Eating Too Fast

  • Serve smaller, more frequent meals
  • Add large rocks to their bowl
  • Invest in puzzle feeders and treat balls
  • Consider an automatic timed pet feeder

For Managing Hairballs

  • Brush frequently to remove excess hair
  • Give hairball remedying treats or foods
  • Add oil to their meals to lubricate passage
  • Schedule regular professional deshedding grooming

For Food Allergies

  • Trial a hypoallergenic or novel protein diet
  • Reintroduce previous foods one at a time
  • Work with your vet to identify the allergen
  • Stick to limited ingredient cat foods

For Parasites

  • Have your vet analyze a fecal sample
  • Deworm using vet recommended medication
  • Give monthly heartworm and flea prevention
  • Keep litter boxes extra clean and scooped

For Inflammatory Bowel Disease

  • Follow your vet’s treatment plan for IBD
  • Transition to prescription gastrointestinal food
  • Identify and eliminate any dietary triggers
  • Manage stress levels which can aggravate IBD

For Foreign Body Obstruction

  • Confine your cat to a safe room without loose objects
  • Check their stool for evidence of an obstruction
  • Visit emergency vet if you suspect a total blockade
  • Limit access to string, tinsel and other risky items

For Abrupt Diet Change

  • Gradually transition new foods over 5-7 days
  • Mix a little more new food and a little less old each meal
  • Keep portions consistent during diet change
  • Stick to one protein source and limit extra treats

When to See the Vet for Undigested Vomiting

Monthly vomiting generally isn’t a major concern. But if your cat is throwing up undigested food consistently or excessively, seek veterinary care.

Take your cat to the vet promptly if vomiting is accompanied by these symptoms:

  • Loss of appetite or difficulty eating
  • Lethargy, depression, or restlessness
  • Significant weight loss
  • Passing blood or black, tarry stool
  • Persistent diarrhea
  • Abdominal tenderness, bloating or enlarged abdomen
  • Difficulty defecating or small, frequent stools
  • Signs of pain like vocalizing or hiding

These symptoms in combination with undigested vomiting indicate an underlying condition requiring prompt veterinary attention and tests. Acting quickly improves the chances of effective treatment.

In particular, immediately contact emergency vet services if your cat shows signs of a foreign body obstruction like vomiting with no food present, retching, weakness, or collapse. This is a life-threatening emergency requiring surgery to remove the blockage. Time is of the essence.

When to Change Your Cat’s Diet

Seeing undigested food regularly in the litter box is also a red flag warranting a diet change. Their food may be too rich, fatty, or contain something their stomach can’t tolerate well.

Try switching your cat to a high quality sensitive stomach formula with these characteristics:

  • Limited ingredients
  • Novel protein source like duck, rabbit, or venison
  • Contains prebiotics or probiotics
  • Higher protein and lower fat
  • Easily digestible carbohydrates like white rice
  • No artificial colors, flavors, or preservatives

Work closely with your veterinarian to select an appropriate new food. Then transition slowly over 5-7 days while monitoring vomiting episodes. This methodical approach reduces upset from abrupt food changes.

Persisting vomiting of undigested food despite the new diet warrants medical investigation to determine if disease is the culprit. Don’t ignore consistent vomiting.

When to Worry About Undigested Vomit

As a cat owner, don’t panic if your feline throws up undigested food occasionally. It’s usually not an emergency. Here are some scenarios when undigested vomiting warrants immediate veterinary care:

  • They vomit repeatedly through the day
  • Episodes happen several days in a row
  • Changes in behavior or energy like lethargy or depression
  • Signs of stomach or abdominal pain
  • Difficulty eating or loss of appetite
  • Vomit contains blood or unusual color/smell
  • Weight loss or muscle wasting

Trust your instincts as a pet parent. If your cat’s vomiting undigested food seems excessive or accompanied by other concerning symptoms, seek medical guidance right away.

How Vets Diagnose Causes of Undigested Vomiting

To get to the source of persistent undigested vomiting in cats, vets use a combination of diagnostic tools:

Complete Medical History – Patterns in vomiting episodes, changes in diet or behavior, and your cat’s health background provide clues. Bring details like date, food eaten, vomit description, etc.

Physical Exam – Checking vitals, palpating the abdomen, listening with a stethoscope, and assessing your cat’s body condition.

Bloodwork – Analysis of a blood sample checks for signs of infection, kidney issues, liver problems, diabetes and more.

Fecal Exam – Microscopic inspection of a stool sample detects intestinal parasites like worms or protozoa.

Diagnostic Imaging – X-rays or ultrasound exams of the abdomen reveal foreign bodies, tumors, organ issues, or blockages.

Endoscopy – A flexible tube with a camera on the end is inserted into the digestive tract to visualize ulcers, cancers, strictures.

Biopsy – Taking tissue samples for microscopic analysis, especially to test for inflammatory bowel disease.

Based on your cat’s presentation, your vet will choose appropriate diagnostics to get to the bottom of the vomiting and rule out various conditions.

What is a Normal Vomiting Frequency in Cats?

As carnivores, cats have a simple and short digestive tract. Hairballs and occasional vomiting are normal. What is not normal is any major change in vomiting pattern or frequency for your individual cat.

Kittens – More prone to vomiting if they eat too quickly or are transitioning between nursing and solid foods.

Adult cats – Typically vomit no more than one to two times per week.

See your vet if your cat’s vomiting exceeds what’s normal for them. Generally more than two episodes per week warrants medical investigation, especially if undigested food is present.

Significant increases in frequency – like vomiting every day or multiple times a day – indicate a greater issue at hand. Seek help sooner rather than later.

How to Care for a Cat with Upset Stomach

Cats with upset stomachs need special care and TLC. Here are some tips for caring for a cat with nausea and vomiting at home:

  • Encourage resting and sleep by providing cozy beds in low noise areas
  • Offer easy to digest foods like plain chicken, pumpkin puree, or bland baby food
  • Ensure access to fresh water to prevent dehydration
  • Slowly reintroduce normal food over 3-5 days after vomiting subsides
  • Clean up accidents right away and use pet-safe enzymatic cleaners
  • Help them feel secure through extra brushing, play, and affection
  • Keep litter boxes extremely clean when stomach is upset
  • Discuss anti-nausea medications and supplements with your vet

Monitor bowel movements and appetite closely. Seek prompt medical attention if vomiting continues beyond 24 hours or other concerning symptoms develop. Sticking to a bland, gentle diet while the stomach heals is key.

When to Seek a Second Opinion for Vomiting

If your cat continues throwing up despite your vet’s treatment, don’t give up. Chronic vomiting warrants a second opinion from a veterinary specialist like an internal medicine expert.

Pursue a referral to a specialist if:

  • Vomiting persists after initial diagnostics and treatment
  • No underlying cause has been identified
  • Your cat’s symptoms are not improving
  • Your vet recommends advanced imaging or procedures
  • You wish to discuss referral options for your cat

Specialists have the tools and experience to conduct more extensive diagnostic testing and explore complex conditions. Getting a fresh perspective could provide answers.

FAQs About Cats Throwing Up Undigested Food:

Is undigested cat vomit an emergency?

Not necessarily. Occasional undigested vomit is quite normal for cats. It becomes an emergency if vomiting is projectile, persistent, or accompanied by symptoms like lethargy, pain, or anorexia.

How can I tell if my cat is vomiting or coughing up hairballs?

Vomit often contains food and fluid. Coughing up hairballs produces straining, gagging, and unproductive retching first. Hairballs are tubular in shape. Vomit is more liquid.

When should I transition my cat to a sensitive stomach food?

If they frequently throw up undigested food, have loose stools, or show signs of a food allergy or intolerance, try transitioning to a sensitive stomach formula.

Do cats outgrow vomiting as kittens?

In most cases yes. Kittens may vomit frequently due to immature digestive systems. Make sure to transition foods properly. Monitor vomiting to ensure it lessens with age.

How can I make my cat’s food more digestible?

Mixing in warm water creates a “cereal” like texture cats can digest easier. Warming chilled canned food helps too. Meat baby foods or small homemade meals are very digestible.

Key Takeaways: Cats Throwing Up Undigested Food

Seeing your cat throw up undigested food can be worrying. In many cases it’s an occasional annoyance, but frequent episodes could mean an underlying health issue needs attention.

Causes range from eating too fast and hairballs to food sensitivities, parasites, foreign bodies, and disease. Take note of behavioral patterns and get vomit samples checked.

Work closely with your vet to diagnose the cause. Treatment focuses on addressing the underlying condition through diet trial, deworming, removing obstructions, or medications.

Monitor vomiting episodes and seek repeat veterinary care if it persists or worsens. Focus on proper, gradual food transitions and creating an environment that reduces stress on your cat’s digestive system.