Why is My Cat Vomiting? Causes and Treatment

Cat vomiting is one of the most common concerns that brings pet owners to the veterinary clinic. While occasional vomiting might be normal for cats—particularly if they're bringing up hairballs—frequent or severe vomiting can indicate serious underlying health problems that require prompt veterinary attention. Understanding the difference between normal and abnormal vomiting, recognizing warning signs, and knowing when to seek help can be crucial for your cat's health and well-being.

Understanding Vomiting vs. Regurgitation

Before discussing causes and treatments, it's important to distinguish between vomiting and regurgitation, as they indicate different problems:

Vomiting

• Active process: Involves abdominal contractions and retching
• Contains digested food: Food has been in stomach and mixed with stomach acid
• Bile present: Often yellow or greenish fluid
• Warning signs: Cats usually show discomfort, drooling, or lip-licking beforehand
• Content appearance: Partially digested, often with bile or foam

Regurgitation

• Passive process: Food comes up without effort or warning
• Contains undigested food: Food hasn't reached stomach yet
• Tubular shape: Often looks like sausage-shaped food
• No bile: Usually just undigested food and saliva
• Immediate: Typically occurs shortly after eating
• Indicates: Usually esophageal problems

Understanding this distinction helps veterinarians diagnose the underlying cause more accurately.

Common Causes of Cat Vomiting

1. Hairballs (Trichobezoars)

Most Common Cause in Cats

Cats are meticulous groomers, and during grooming, they ingest loose hair that can accumulate in the stomach:

Normal Hairball Frequency:

• Once or twice per month is typically normal
• Long-haired breeds more prone
• Seasonal increases during shedding periods

Concerning Signs:

• More than 2-3 per month
• Difficulty passing hairballs
• Loss of appetite
• Constipation or diarrhea
• Lethargy

Prevention:

• Regular brushing (daily for long-haired cats)
• Hairball-control diets
• Fiber supplements
• Specialized treats or lubricants

2. Dietary Indiscretion and Food Changes

Eating Inappropriate Items:

• Eating too quickly (scarfing)
• Consuming spoiled food
• Eating plants or grass
• Ingesting foreign objects
• Table scraps or human food

Sudden Diet Changes:

• Switching food brands too quickly
• New treats or supplements
• Changes in feeding schedule
• Food allergies or sensitivities

Prevention:

• Gradual diet transitions (7-10 days)
• Consistent feeding schedule
• Slow-feeder bowls
• Keep human food away
• Remove toxic plants

3. Food Allergies and Intolerances

Cats can develop sensitivities to certain proteins or ingredients:

Common Allergens:

• Beef
• Dairy products
• Fish
• Chicken
• Wheat/gluten

Associated Symptoms:

• Chronic vomiting
• Diarrhea
• Skin problems (itching, rashes)
• Ear infections
• Weight loss

Diagnosis and Treatment:

• Elimination diet trials (8-12 weeks)
• Hypoallergenic prescription diets
• Novel protein sources
• Lifetime dietary management

4. Inflammatory Bowel Disease (IBD)

Chronic inflammation of the gastrointestinal tract:

Symptoms:

• Chronic or intermittent vomiting
• Diarrhea (may contain blood or mucus)
• Weight loss despite good appetite
• Poor coat quality
• Lethargy

Diagnosis:

• Blood work and fecal tests
• Imaging (ultrasound, X-rays)
• Intestinal biopsy (definitive diagnosis)
• Rule out other conditions

Treatment:

• Dietary modification (novel proteins, hydrolyzed diets)
• Anti-inflammatory medications
• Immunosuppressive drugs
• Antibiotics (for bacterial overgrowth)
• Probiotics
• Long-term management required

5. Kidney Disease (Chronic Renal Failure)

Very common in older cats, kidney disease often presents with vomiting:

Symptoms:

• Increased drinking and urination
• Decreased appetite
• Weight loss
• Lethargy
• Bad breath (uremic odor)
• Mouth ulcers

Diagnosis:

• Blood work (elevated kidney values)
• Urinalysis
• Blood pressure measurement
• SDMA testing (early detection)

Treatment:

• Prescription renal diets (reduced protein and phosphorus)
• Subcutaneous fluids
• Phosphate binders
• Blood pressure medications
• Appetite stimulants
• Anti-nausea medications
• Regular monitoring

6. Hyperthyroidism

Common endocrine disorder in middle-aged to older cats:

Symptoms:

• Increased appetite with weight loss
• Vomiting
• Diarrhea
• Hyperactivity or restlessness
• Increased vocalization
• Poor coat quality
• Rapid heart rate

Diagnosis:

• Blood test measuring T4 levels
• Physical examination (thyroid nodules)

Treatment Options:

• Oral medication (methimazole) - lifelong
• Prescription diet (iodine-restricted)
• Radioactive iodine therapy (curative)
• Surgical removal of thyroid gland

7. Pancreatitis

Inflammation of the pancreas, can be acute or chronic:

Symptoms:

• Acute vomiting
• Abdominal pain (hunched posture, reluctance to move)
• Loss of appetite
• Lethargy
• Fever
• Diarrhea
• Dehydration

Risk Factors:

• High-fat diets
• Obesity
• Trauma
• Infections
• Medications

Diagnosis:

• Blood work (feline pancreatic lipase)
• Abdominal ultrasound
• Physical examination

Treatment:

• Hospitalization with IV fluids
• Pain management
• Anti-nausea medications
• Nutritional support
• Treatment of underlying causes
• Low-fat diet long-term

8. Foreign Objects and Intestinal Obstructions

Cats, especially kittens, may ingest non-food items:

Common Culprits:

• String, yarn, or thread
• Rubber bands
• Hair ties
• Small toys
• Tinsel (especially dangerous)
• Plastic wrappers

Symptoms:

• Acute vomiting
• Loss of appetite
• Abdominal pain
• Lethargy
• Constipation or straining
• Visible string from mouth or anus (DO NOT PULL)

Emergency Situation:

• Immediate veterinary care required
• Imaging (X-rays, ultrasound)
• Often requires surgery
• Can be life-threatening

9. Toxins and Poisoning

Cats are sensitive to many substances toxic to them:

Common Toxins:

• Lilies (all parts, extremely toxic)
• Antifreeze (ethylene glycol)
• Human medications (acetaminophen, ibuprofen)
• Household cleaners
• Insecticides
• Rat poison
• Essential oils
• Certain houseplants

Symptoms:

• Acute vomiting
• Drooling
• Tremors or seizures
• Difficulty breathing
• Collapse
• Dilated pupils

Emergency Treatment:

• Immediate veterinary care
• Bring toxin container/plant
• Decontamination
• Supportive care
• Specific antidotes when available

10. Gastrointestinal Parasites

Intestinal worms can cause vomiting, especially in kittens:

Common Parasites:

• Roundworms
• Hookworms
• Tapeworms
• Giardia
• Coccidia

Symptoms:

• Vomiting
• Diarrhea
• Weight loss or failure to gain weight
• Pot-bellied appearance
• Dull coat
• Visible worms in vomit or feces

Treatment:

• Fecal examination
• Deworming medications
• Repeat treatments as needed
• Environmental decontamination
• Prevent through regular preventives

11. Cancer

Various cancers can cause vomiting in cats:

Types:

• Lymphoma (most common GI cancer)
• Adenocarcinoma
• Mast cell tumors
• Liver or pancreatic cancer

Symptoms:

• Chronic vomiting
• Progressive weight loss
• Decreased appetite
• Lethargy
• Palpable abdominal masses

Diagnosis:

• Imaging (X-rays, ultrasound, CT scan)
• Biopsy
• Blood work
• Fine needle aspirate

Treatment:

• Depends on cancer type and stage
• Chemotherapy
• Surgery
• Radiation therapy
• Palliative care

When to See a Veterinarian Immediately

Emergency Symptoms:

• Continuous vomiting (more than 2-3 times in 24 hours)
• Blood in vomit (red or coffee-ground appearance)
• Signs of pain (crying, hiding, hunched posture)
• Lethargy or weakness
• Loss of appetite for more than 24 hours
• Diarrhea accompanying vomiting
• Distended or painful abdomen
• Pale gums or yellow discoloration (jaundice)
• Difficulty breathing
• Seizures or collapse
• Known toxin ingestion
• Suspected foreign body

Schedule Veterinary Appointment:

• Chronic vomiting (more than once weekly)
• Unexplained weight loss
• Change in appetite or thirst
• Behavioral changes
• Poor coat quality
• Increased frequency of hairballs

Diagnostic Approach

Your veterinarian will take a systematic approach to diagnosis:

Medical History

• Duration and frequency of vomiting
• Description of vomit (color, content, consistency)
• Diet history
• Access to toxins or foreign objects
• Other symptoms
• Previous health issues

Physical Examination

• Overall condition assessment
• Hydration status
• Abdominal palpation
• Oral examination
• Temperature, heart rate, respiratory rate
• Body condition score

Diagnostic Tests

Initial Testing:

• Complete blood count (CBC)
• Blood chemistry panel
• Urinalysis
• Fecal examination
• Thyroid testing (older cats)

Advanced Diagnostics:

• Abdominal X-rays
• Abdominal ultrasound
• Specific blood tests (fPLI, SDMA)
• Endoscopy
• Exploratory surgery
• Biopsies
• CT scan or MRI

Treatment Options

Treatment depends on the underlying cause and severity:

Supportive Care

For Mild Cases:

• Withhold food for 12-24 hours (with veterinary guidance)
• Gradual reintroduction of bland diet
• Small, frequent meals
• Ensure water availability
• Monitor closely

For Moderate to Severe Cases:

• Hospitalization: Intensive care monitoring
• IV Fluids: Correct dehydration and electrolyte imbalances
• Anti-nausea Medications: Maropitant (Cerenia), ondansetron
• Antacids: Famotidine, omeprazole
• Pain Management: If indicated
• Nutritional Support: Appetite stimulants, feeding tubes if needed

Specific Treatments

Based on diagnosis:

• Antibiotics: For bacterial infections
• Antiparasitics: For intestinal parasites
• Anti-inflammatory drugs: For IBD
• Chemotherapy: For cancer
• Surgery: For foreign bodies, tumors, or obstructions
• Dietary management: Prescription diets for specific conditions
• Medications: For chronic diseases (kidney disease, hyperthyroidism)

Long-Term Management

For Chronic Conditions:

• Regular veterinary checkups
• Consistent medication administration
• Dietary compliance
• Environmental modifications
• Stress reduction
• Weight management
• Monitor for changes

Home Care and Prevention

Feeding Management

1. Consistent Schedule:

   • Feed at same times daily
   • Multiple small meals better than large meals
   • Avoid free-feeding in multi-cat households

2. Diet Quality:

   • High-quality, appropriate cat food
   • Age-appropriate formulations
   • Consider sensitive stomach formulas
   • Adequate hydration (wet food helps)

3. Slow Eating:

   • Puzzle feeders
   • Slow-feed bowls
   • Separate feeding areas for multiple cats

Environmental Management

1. Reduce Stress:

   • Consistent routine
   • Safe hiding spaces
   • Vertical territory (cat trees)
   • Litter box management (one per cat plus one)
   • Gradual introductions of changes

2. Safety:

   • Remove toxic plants
   • Secure human medications
   • Store cleaning products safely
   • Keep small objects away
   • Block access to dangerous areas

3. Hairball Prevention:

   • Daily brushing
   • Hairball remedies (petroleum-based lubricants)
   • High-fiber diets
   • Adequate hydration

When to Monitor Closely

• After dietary changes
• During stressful events (moving, new pets)
• After medication changes
• Senior cats (7+ years)
• Cats with chronic conditions

Copenhagen Cat Owner Considerations

At MyPeterinarian in Copenhagen, we see various vomiting cases in cats:

Common Local Factors:

• Indoor lifestyle: Common in Copenhagen apartments; may increase hairball frequency
• Diet availability: Access to high-quality European cat foods
• Seasonal changes: Danish weather changes can affect cats
• Stress factors: Urban environment considerations

Our Services:

• 24/7 emergency care for acute vomiting
• Comprehensive diagnostic capabilities
• Specialist referrals when needed
• Long-term disease management
• Nutritional counseling

Prognosis

The outlook depends entirely on the underlying cause:

Excellent Prognosis:

• Dietary indiscretion
• Hairballs
• Mild food intolerance
• Intestinal parasites

Good Prognosis with Treatment:

• Hyperthyroidism
• Early kidney disease
• IBD with proper management
• Foreign bodies (with prompt removal)

Guarded to Poor Prognosis:

• Advanced kidney disease
• Certain cancers
• Severe pancreatitis
• Liver disease

Early intervention generally improves outcomes for most conditions.

Conclusion

While occasional vomiting might be normal for cats, persistent or severe vomiting always warrants veterinary attention. As a cat owner, you know your pet best—trust your instincts if something seems wrong. Many causes of vomiting are treatable, especially when caught early. Regular veterinary care, proper nutrition, a safe environment, and attentive monitoring are your best defenses against serious vomiting-related health issues.

Don't wait to seek help if your cat's vomiting seems abnormal or if you notice other concerning symptoms. Prompt diagnosis and treatment can prevent complications and keep your feline companion healthy and comfortable.

Is your cat vomiting? Contact MyPeterinarian in Copenhagen today to schedule an examination. Our experienced veterinary team can diagnose the cause and provide effective treatment to get your cat feeling better quickly. We're here for your cat's health 24/7—don't hesitate to reach out!