CONDITION

Gastroenteritis in Cats

Why this matters now

Gastroenteritis can occur at any age and may develop suddenly following dietary indiscretion, stress, infection, or toxin exposure. Some cases arise during seasonal changes or after boarding. Young cats and those with outdoor access may face higher exposure to infectious causes.

Episodes may begin with reduced appetite and progress to vomiting and diarrhoea. Mild cases often resolve within a few days, whilst more severe episodes can lead to dehydration and electrolyte disturbances. Some cats experience recurrent episodes that may warrant investigation for underlying conditions.

Signals & patterns

Early signals

Reduced interest in food

Cats may sniff at food then walk away, or eat smaller amounts than usual.

Increased grass eating or unusual chewing

Some cats seek out grass or other materials when feeling nauseous.

Subtle lethargy or quietness

Affected cats may be less interactive or sleep more than usual.

Increased lip licking or swallowing

Signs of nausea may include repeated swallowing or drooling.

Later signals

Vomiting

Episodes may contain undigested food, bile, or clear fluid. Frequency and timing provide useful information.

Diarrhoea

Stools may range from soft to watery and may contain mucus or blood in some cases.

Dehydration signs

Reduced skin elasticity, dry gums, and sunken eyes may indicate fluid loss.

Hiding or withdrawal

Cats feeling unwell often seek isolated spots and avoid interaction.

Click to read about the biological mechanisms

How this is usually investigated

Investigation depends on severity and duration. Mild, short-lived episodes may not require extensive testing, whilst persistent or severe cases warrant more detailed evaluation.

Physical examination

Purpose: To assess hydration status, abdominal comfort, and overall condition
Considerations: Palpation may reveal pain, masses, or thickened bowel loops. Body condition and hydration guide supportive care needs.

Blood tests

Purpose: To evaluate organ function, hydration status, and check for systemic illness
Considerations: May reveal dehydration, electrolyte imbalances, or underlying conditions such as kidney disease or hyperthyroidism that can present similarly.

Faecal examination

Purpose: To check for parasites, bacterial overgrowth, or blood
Considerations: Important for cats with outdoor access or recurrent episodes. Some parasites require specific tests.

Imaging

Purpose: To visualise abdominal structures and check for obstructions or masses
Considerations: Radiographs or ultrasound may be indicated if obstruction is suspected or symptoms persist.

Infectious disease testing

Purpose: To identify viral causes such as feline parvovirus
Considerations: May be important in unvaccinated cats or those from high-risk environments.

Options & trade-offs

Management depends on severity and underlying cause. Various approaches may be appropriate for different situations.

Supportive care and fluid therapy

Maintaining hydration through oral or intravenous fluids whilst the gut recovers.

Trade-offs: Mild cases may manage with encouraged water intake at home, whilst more severe cases may need veterinary fluid support.

Dietary management

Temporary feeding of easily digestible foods, sometimes following a brief period of gut rest.

Trade-offs: Cats should not be without food for extended periods. Highly digestible diets support recovery whilst reducing gut workload.

Anti-nausea medications

Medications to reduce vomiting and improve comfort.

Trade-offs: Can help cats feel well enough to eat and drink. Various options exist with different administration routes.

Probiotics and gut support

Supplements aimed at supporting intestinal bacterial balance during recovery.

Trade-offs: May help restore normal gut flora. Evidence varies for different products and situations.

Treatment of specific causes

Targeted therapy if parasites, bacteria, or other specific causes are identified.

Trade-offs: Depends on accurate diagnosis. Some infections require specific antimicrobial treatment.

Common misconceptions

Misconception:

"Occasional vomiting in cats is always normal"

Reality:

Whilst occasional hairballs occur, regular vomiting warrants attention. Cats may hide illness, so changes from their normal pattern can be significant.

Misconception:

"Withholding food for 24 hours is always helpful"

Reality:

Whilst brief gut rest may sometimes be appropriate, cats have unique metabolic requirements that make prolonged fasting potentially harmful, particularly for overweight cats.

Misconception:

"Dairy products help settle cat stomachs"

Reality:

Most adult cats are lactose intolerant, and dairy products may actually worsen gastrointestinal symptoms.

Monitoring the frequency and character of vomiting and diarrhoea provides useful information, as does tracking food and water intake. Noting whether the cat remains alert and interactive, or has become withdrawn, helps assess severity. If symptoms persist beyond a day or two, or if the cat appears significantly unwell, further evaluation may be appropriate.

Last reviewed: 24 April 2026 · Dr Alastair Greenway MRCVS