Over a day of persistent diarrhoea in your cat can indicate dietary upset, parasites, infection or a systemic problem, so you should withhold food for 12–24 hours, offer fresh water and collect a stool sample for testing. Routine checks and preventive care are covered by our Pet Wellness Plan, and keeping parasite and vaccine schedules current helps — see our Harrogate Vaccinations. If symptoms continue or your cat seems unwell, book a consultation with our Harrogate vets.
Common Causes of Diarrhea in Cats
Diarrhea often stems from a handful of repeatable causes: abrupt diet changes, infections (viral, bacterial, protozoal), intestinal parasites, inflammatory bowel disease, toxins or stress-related gut upset. Kittens and outdoor cats show higher infection and parasite rates, while older cats more commonly have chronic conditions. Many preventable causes are reduced through routine care covered by our Pet Wellness Plan.
Dietary Changes
Sudden switches in food, new treats or too many table scraps can cause loose stools within 24–72 hours; high‑fat meals may even trigger pancreatitis. Aim to transition diets over 7–10 days, increasing the new food by about 10–25% daily. You can run a 2–3 week elimination trial with a novel or hydrolysed diet to spot intolerances, and track frequency, volume and any blood or mucus in the stool.
Infections and Parasites
Viruses like feline panleukopenia, bacteria such as Salmonella or Campylobacter, protozoa (Giardia, coccidia) and worms (roundworms, hookworms) all produce diarrhoea; outbreaks are common in shelters and multi‑cat households. Young cats are especially vulnerable and some viral causes are preventable during your cat’s vaccination appointments.
Diagnostics usually start with a faecal float or PCR to identify parasites and pathogens, plus bloods if systemic signs appear; treatment ranges from fenbendazole or praziquantel for worms to targeted antibiotics or antiprotozoals when indicated, and IV or SC fluids for dehydration. Zoonotic risks (Toxocara, Salmonella) mean you should avoid direct contact with stool; if diarrhoea lasts more than 48 hours, contains blood, or your cat becomes lethargic or vomits repeatedly, you can book a consultation with our vets for prompt assessment and treatment.
Signs to Watch For
Look for changes in frequency, consistency and colour: normal cats pass formed stools once or twice daily, so more than three loose stools in 24 hours or sudden watery, mucous or bloody faeces is a red flag. Note vomiting, appetite changes, weight loss or dehydration (sunken eyes, tacky gums) and collect a fresh stool sample and photos with timestamps to bring in — long-term monitoring and preventive health can be covered by our Pet Wellness Plan.
Severity of Diarrhea
Differentiate acute from chronic: acute diarrhoea usually resolves within 48 hours, while chronic diarrhoea persists beyond two weeks and needs investigation. Seek urgent care if stools are bloody, tarry, or very watery, if your cat has more than 3–4 loose stools a day, shows collapse or marked lethargy, or exhibits signs of dehydration such as poor skin elasticity and reduced urine output.
Other Accompanying Symptoms
Note vomiting, fever, abdominal pain, marked inappetence, sudden weight loss, or persistent straining — these point to systemic disease, parasites or obstruction. If you observe any of these alongside diarrhoea, you can book a consultation with our vets to arrange faecal testing, blood work or imaging promptly.
Vomiting plus diarrhoea can indicate viral infections (e.g., panleukopenia), severe bacterial enteritis, or foreign body obstruction; fever over 39.5°C suggests infection, while pale gums or rapid breathing signal shock or anaemia. Bring a fresh stool sample, note recent diet changes or toxin exposure, and discuss parasite control and catch‑up care during your pet’s vaccination appointments if your cat is due for preventive measures.
Home Remedies for Mild Cases
Withhold food for 12–24 hours for adult cats (never for kittens), then offer small, bland wet meals and watch appetite, energy and stool for 24–48 hours; examples include boiled skinless chicken mixed into a canned gastrointestinal diet or 1 tsp plain canned pumpkin to add fibre. If diarrhoea recurs, contains blood, or your cat becomes lethargic, discuss these patterns as part of our Pet Wellness Plan.
Dietary Adjustments
After the fast, feed 1–2 tablespoons of bland wet food every 3–4 hours—boiled white fish or chicken are good choices; add ½–1 tsp canned pumpkin per meal for soluble fibre. Avoid cow’s milk, fatty leftovers and abrupt diet switches. Use a feline-specific probiotic per label directions (single-strain Enterococcus or Bifidobacterium formulations are common). Transition back to the regular diet slowly over 3–5 days once stools firm.
Hydration
Fresh water should be available at all times and switching to wet food helps—canned food contains about 70–75% moisture versus ~10% in dry kibbles, which reliably increases intake. Encourage drinking with a shallow bowl or pet fountain; syringe small 5–10 ml sips for cats that won’t lap. Monitor urine output and gum moisture; reduced urination or tacky gums require further attention.
Assess dehydration quantitatively: 5% = mild (slight skin elasticity loss), 5–8% = moderate (dry mucous membranes, slower skin return), >10% = severe (shock risk). Offer 5–10 ml fluids every 10–15 minutes by syringe if the cat is alert, but avoid large home boluses. Persistent signs, inability to keep fluids down or worsening lethargy mean your cat will likely need subcutaneous or IV fluids—bring this up during your pet’s vaccination appointments so it’s included in preventive care planning.
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When to See a Vet
Seek veterinary attention if your cat’s diarrhea is severe, contains blood, or continues beyond 48 hours in an adult (24–48 hours in kittens or elderly). Vomiting alongside diarrhea, marked lethargy, loss of appetite, or dehydration signs (sunken eyes, tacky gums) also demand assessment. For routine monitoring and preventive follow-up you might make use of part of our Pet Wellness Plan. If you’re unsure how urgent it is, you can book a consultation with our vets for advice and testing.
Persistent Diarrhea
Diarrhea that lasts more than 48–72 hours, recurs after seeming to improve, or causes steady weight loss needs diagnostics: bring a fresh stool sample, list recent diet changes and medications. Fecal parasite screens, Giardia tests and basic bloods commonly identify causes; dietary intolerance and chronic inflammatory bowel disease are frequent culprits. Young kittens and immunosuppressed cats deteriorate quickly, and if vaccination or preventive care status is unclear check our Harrogate Vaccinations information when arranging follow-up.
Symptoms Indicating Serious Issues
Seek emergency care for dark, tarry or bright red stools, collapse, persistent vomiting, rapid breathing, pale or yellow gums, or a temperature above ~39.5°C or below ~37°C. Existing conditions like kidney disease or diabetes raise risk of complications. These signs can indicate bleeding, severe infection, toxin ingestion or organ failure and frequently require immediate fluids, blood tests and imaging.
Assess dehydration by checking skin tent, capillary refill (normally under 2 seconds) and gum moisture; marked dehydration typically needs IV or subcutaneous fluids. Expect initial diagnostics to include PCV/TS, biochemistry, electrolytes and abdominal imaging, with faecal PCR or parasite tests as needed. Treatments range from outpatient diet and fluid therapy to hospitalisation for IV fluids, antiemetics, antibiotics or blood transfusion if there’s severe blood loss—note recent medications and appetite to speed diagnosis.
Diagnostic Procedures at the Vet
Physical Examination
You bring your cat in and the vet records temperature (normal 38.1–39.2°C), checks heart and lung sounds, palpates the abdomen for pain, masses or thickened intestines, assesses hydration via skin tenting and mucous membrane colour, and measures weight and body condition; findings such as fever, dehydration or palpable abnormalities determine whether immediate fluids, pain relief or urgent diagnostics are needed.
Diagnostic Tests
Routine in-clinic tests include faecal flotation and direct smear for worms and protozoa, SNAP giardia (~10-minute result) and FeLV/FIV screens, plus bloods (CBC, biochemistry, electrolytes) to identify infection, anaemia or electrolyte loss; radiographs or abdominal ultrasound evaluate obstructions or masses, while PCR and cultures often take 48–72 hours for definitive infectious identification.
When diarrhoea is persistent (>2 weeks) or severe, vets add targeted tests: faecal PCR panels for Giardia/Cryptosporidium, serum fPL for pancreatitis, total T4 in older cats, and endoscopy or full‑thickness biopsy under anaesthesia to distinguish IBD from lymphoma (histopathology typically returns in 7–10 days). Routine faecal testing and preventive deworming are part of our Pet Wellness Plan, and if you need tailored advice you can book a consultation with our vets.
Treatment Options for Diarrhea
Medications
Your vet may prescribe short courses of metronidazole or tylosin for suspected bacterial causes, fenbendazole for common parasites, and probiotics such as Enterococcus faecium to help restore gut flora. Antiemetics (for example maropitant) and subcutaneous or IV fluids treat dehydration and ongoing vomiting. Avoid over-the-counter human remedies—dosing errors can be dangerous. Routine parasite control and some preventive checks are covered by our Pet Wellness Plan.
Follow-up Care
Keep a stool diary recording frequency, consistency, blood or mucus and any appetite or behaviour changes; photograph samples if you can. Contact your vet earlier if your cat becomes lethargic, vomits repeatedly or shows signs of dehydration, and arrange a recheck if diarrhoea persists beyond 48–72 hours.
Schedule a recheck 48–72 hours after treatment starts so the vet can assess response and run repeat faecal tests, bloodwork or ultrasound for persistent cases. Chronic diarrhoea often needs a 6–8 week hypoallergenic or novel‑protein diet trial and medication adjustments; bring medication lists and onset notes, and raise these points during routine preventive visits such as vaccination appointments at our Harrogate Vaccinations.
If you’re unsure whether your cat needs an appointment, you can book a consultation with our vets for personalised advice.
Final Words
Hence, if your cat has diarrhea you should watch for dehydration, ensure your cat drinks, withhold food for 12–24 hours then reintroduce a bland diet, and seek urgent care for bloody stools, vomiting or severe lethargy; make prevention part of our Pet Wellness Plan and keep up with parasite control and vaccines during routine vaccination appointments; if symptoms persist or you’re worried, book a consultation with our Harrogate vets to get personalised advice.
FAQ
Q: Why does my cat have diarrhoea?
A: Diarrhoea in cats can be caused by short-term issues like sudden diet change, eating rubbish or a new treat, food intolerance or a minor stomach bug; infectious agents such as bacteria, viruses or parasites (worms, Giardia); reactions to medications; stress or anxiety; and chronic conditions such as inflammatory bowel disease, pancreatitis, kidney or liver disease, and hyperthyroidism. Vaccination reactions are uncommon, but keeping your pet’s preventive care up to date helps reduce infectious causes — for info on routine preventive measures see our Harrogate Vaccinations page.
Q: What should I do at home right away?
A: Check your cat’s overall behaviour and appetite, and make sure fresh water is always available to avoid dehydration. Collect a fresh stool sample and note how long the diarrhoea has been happening, any blood in the stool, vomiting, or changes in appetite or drinking. Do not give human anti-diarrhoeal medicines. If your cat is bright and only mildly affected, you can offer small, bland meals (small amounts frequently) and monitor closely. Avoid prolonged fasting in cats because they can develop hepatic lipidosis; if symptoms are moderate or there’s any vomiting, call your vet for advice.
Q: How should I manage my cat’s diet and supplements?
A: Offer small portions of a bland, easily digestible diet and transition back to their normal food over 3–5 days as stools improve. Probiotics formulated for cats can help some cases, but don’t start prescription diets or medications without veterinary guidance. If diarrhoea is recurrent or linked to food, your vet may recommend a hypoallergenic or prescription gastrointestinal diet and investigations to find an underlying cause — ongoing preventive and wellness support for conditions like this can be covered by our Pet Wellness Plan.
Q: What are the warning signs that mean I should see a vet urgently?
A: Seek immediate veterinary attention if your cat has any of the following: severe lethargy, collapse, repeated vomiting, blood in vomit or faeces, signs of dehydration (sunken eyes, tacky gums, weak or rapid heartbeat), very high or low body temperature, severe abdominal pain, or if a kitten, elderly or immunocompromised cat becomes unwell. Rapid deterioration or inability to keep water down are emergencies.
Q: What will the vet do to diagnose and treat diarrhoea?
A: The vet will take a full history and perform a physical exam, check hydration and weight, and may request faecal tests for parasites, bacterial cultures, or PCR for specific pathogens. Blood tests, urine analysis, abdominal X-rays or ultrasound can identify systemic or obstructive causes. Treatment may include fluid therapy (subcutaneous or intravenous), parasite treatments, antibiotics if indicated, anti-emetics, pain relief, prescription diets, or hospital monitoring for severe cases. For ongoing or recurrent problems your vet will discuss long-term management and further testing to find underlying disease.
If you’re unsure whether your cat needs veterinary attention, book a consultation with our Harrogate vets to get personalised advice.