Quick answer
Key points
- Most mild diarrhoea improves within 24–48 hours, but diarrhoea lasting over 24 hours or coming with other signs needs a vet check.
- Kittens and puppies are more vulnerable to dehydration and serious illness, so diarrhoea in a young animal always needs a vet's advice.
- Blood or mucus in the stool, black tarry stools, vomiting, lethargy and refusing food are warning signs.
- Common causes include sudden diet changes, fatty food, milk and worms; parvovirus and panleukopenia are dangerous causes.
- Do not give human diarrhoea medicine or over-the-counter remedies without a vet's advice, as some can harm pets.
When should you see a vet?
- See a vet immediately if your pet is very weak or collapses, vomits repeatedly, has bloody or black tarry diarrhoea, or shows dehydration signs such as sticky gums and sunken eyes.
- A puppy or kitten with diarrhoea, especially one that is not fully vaccinated.
- Diarrhoea for more than 24 hours, or very watery, constant diarrhoea.
- Diarrhoea with vomiting, refusing food or water, or a painful belly.
- An elderly pet, a pet with another illness, or a pet taking medication.
- Your pet may have swallowed a poison, human medicine or a foreign object.
Contact your nearest veterinarian or animal clinic. This site cannot assess your animal’s condition. Choosing a vet
In this guide (11)
Is diarrhoea in cats and dogs dangerous?
Most mild diarrhoea settles within 24–48 hours, but some cases are serious and need a vet. PDSA explains that a pet that seems unwell, or has had diarrhoea for more than 24 hours, should be checked. According to International Cat Care (ICC), diarrhoea means soft, liquid or watery faeces, caused by gut contents moving too fast so that less water and nutrients are absorbed. The colour may be lighter or darker than usual, or coated in mucus. The Cornell Feline Health Center notes that diarrhoea can be brief and harmless, but it can also signal a life-threatening disease. PDSA adds that severe or untreated diarrhoea can lead to dehydration and serious illness.
Evidence: PDSA — Dog diarrhoea ↗ · PDSA — Diarrhoea in cats ↗ · International Cat Care — Diarrhoea in cats ↗ · Cornell Feline Health Center — Diarrhea ↗
What causes diarrhoea in cats and dogs?
Common causes of diarrhoea are a sudden change of food, eating something unusual or fatty, worms and gut parasites such as giardia. PDSA also lists food allergies, bacterial infections such as Salmonella and Campylobacter, bowel inflammation, blockages from swallowed objects, pancreatitis, and liver and kidney disease. Cornell adds stress, for example a long car journey, and an overactive thyroid gland in cats. Milk is another frequent trigger: the ASPCA explains that pets lack enough of the enzyme lactase, so milk and dairy products can cause diarrhoea, and Cornell notes that many cats are lactose-intolerant. Dangerous causes include parvovirus in dogs, and panleukopenia and FIP in cats.
Evidence: PDSA — Dog diarrhoea ↗ · PDSA — Diarrhoea in cats ↗ · Cornell Feline Health Center — Diarrhea ↗ · ASPCA Animal Poison Control — People Foods to Avoid Feeding Your Pets ↗ · Cornell Feline Health Center — Feeding Your Cat ↗
Why is diarrhoea more dangerous in puppies and kittens?
Puppies and kittens are more vulnerable to dehydration, and diarrhoea in them can signal a deadly viral infection. PDSA advises always contacting your vet if a kitten or elderly cat has diarrhoea, because they are more at risk of dehydration, and seeking advice for a puppy with diarrhoea because it can be more serious. Parvovirus causes severe, foul-smelling and often bloody diarrhoea; PDSA says it is nearly always fatal without treatment and especially dangerous for puppies and unvaccinated dogs. In cats, Cornell lists panleukopenia as one of the serious causes of diarrhoea.
Research in Indonesia shows why vaccination matters. A Universitas Udayana study in Denpasar found that dogs with incomplete vaccination were about 10 times more likely to get parvo, and puppies aged 0–3 months about 3 times more likely. A Universitas Gadjah Mada study in Yogyakarta found that vaccination status and the arrival of a new cat were the strongest risk factors for panleukopenia, alongside cats of stray origin and cats that spend time outdoors. So diarrhoea in a young animal that is not fully vaccinated needs a vet check straight away.
Evidence: PDSA — Diarrhoea in cats ↗ · PDSA — Dog diarrhoea ↗ · PDSA — Parvovirus in dogs ↗ · Cornell Feline Health Center — Diarrhea ↗ · Jurnal Veteriner (Universitas Udayana) — Prevalensi dan Faktor Risiko Penyakit Virus Parvo pada Anjing di Denpasar ↗ · Jurnal Sain Veteriner (UGM) — Faktor Risiko Feline Panleukopenia pada Kucing di Daerah Istimewa Yogyakarta ↗
What are the signs of dehydration in cats and dogs?
Signs of dehydration include dry, sticky gums, sunken and dry-looking eyes, lethargy and skin that has lost its elasticity. An American Kennel Club (AKC) article reviewed by its chief veterinarian also lists loss of appetite, a dry nose, thick saliva and panting. The AKC notes that sudden bouts of vomiting and diarrhoea can cause dehydration, and that a pet with dehydration signs or persistent vomiting should go to the vet immediately as an emergency. PDSA also lists sticky gums and sunken eyes as reasons to contact your vet. ICC explains that more severe diarrhoea can leave cats dehydrated. Do not wait for these signs to appear in a kitten or puppy with diarrhoea.
Evidence: American Kennel Club — Dehydration in Dogs: Signs, Symptoms, Treatments ↗ · PDSA — Vomiting in dogs ↗ · International Cat Care — Diarrhoea in cats ↗
When does a cat or dog with diarrhoea need a vet straight away?
Contact a vet straight away if the stool contains blood or mucus, or your pet has very watery or constant diarrhoea, vomiting, lethargy, no appetite or a painful belly. PDSA also advises prompt contact if diarrhoea lasts over 24 hours, or if the pet is very young or old, has another illness or takes medication. A dog with a painful belly may yelp when lifted, or stand with its front legs down and rear end raised. ICC explains that black, tarry stools can mean bleeding higher up in the gut and should be reported to the vet. Cornell advises veterinary care as soon as possible if diarrhoea lasts more than a day or two with poor appetite, lethargy or vomiting.
Evidence: PDSA — Dog diarrhoea ↗ · PDSA — Diarrhoea in cats ↗ · International Cat Care — Diarrhoea in cats ↗ · Cornell Feline Health Center — Diarrhea ↗
Can you give human diarrhoea medicine to a cat or dog?
No. Do not give human diarrhoea medicine or over-the-counter remedies without a vet's advice. Cornell stresses that some over-the-counter medicines can be harmful to cats, so a vet should examine the animal as soon as signs appear. PDSA explains that antibiotics are rarely needed for diarrhoea in cats and, in the wrong situation, can make it worse by killing friendly gut bacteria. The right treatment depends on the cause. According to ICC, vets may test faecal samples for parasites and infections, run blood and urine tests, or use imaging such as X-rays and ultrasound.
Before you go, note when the diarrhoea started, how often it happens, its colour and consistency, and whether there is blood, mucus or straining, as ICC suggests. Also mention any diet change, possible access to rubbish, medicines or chemicals, vaccination status and other signs. In Indonesia, pets can be examined at veterinary clinics and at some government facilities, such as the Batam city puskeswan and the Jakarta Dinas KPKP mobile animal clinics. Check services and opening hours before you go.
Evidence: Cornell Feline Health Center — Diarrhea ↗ · PDSA — Diarrhoea in cats ↗ · International Cat Care — Diarrhoea in cats ↗ · Puskeswan Kota Batam — Layanan ↗ · Dinas KPKP Provinsi DKI Jakarta — Dinas KPKP DKI Jakarta Luncurkan 5 Unit Mobil Klinik Hewan Keliling ↗
How can you help prevent diarrhoea in cats and dogs?
Change food gradually, keep pets away from rubbish and fatty human food, do not give milk, and complete vaccinations as your vet advises. PDSA lists sudden diet changes and rich, fatty food as common causes of diarrhoea. Milk and dairy products can trigger diarrhoea because pets lack lactase, according to the ASPCA. PDSA calls vaccination the best way to prevent parvovirus, and researchers in Yogyakarta concluded that vaccination and quarantine of new animals are important to prevent panleukopenia. That study also found outdoor waste disposal to be one of the risk factors. Ask your vet about a suitable worming schedule, because worms are a common cause of diarrhoea.
Evidence: PDSA — Dog diarrhoea ↗ · PDSA — Diarrhoea in cats ↗ · ASPCA Animal Poison Control — People Foods to Avoid Feeding Your Pets ↗ · PDSA — Parvovirus in dogs ↗ · Jurnal Sain Veteriner (UGM) — Faktor Risiko Feline Panleukopenia pada Kucing di Daerah Istimewa Yogyakarta ↗
Sources & references
- PDSA — Dog diarrhoea ↗
- PDSA — Diarrhoea in cats ↗
- International Cat Care — Diarrhoea in cats ↗
- Cornell Feline Health Center — Diarrhea ↗
- ASPCA Animal Poison Control — People Foods to Avoid Feeding Your Pets ↗
- Cornell Feline Health Center — Feeding Your Cat ↗
- PDSA — Parvovirus in dogs ↗
- Jurnal Veteriner (Universitas Udayana) — Prevalensi dan Faktor Risiko Penyakit Virus Parvo pada Anjing di Denpasar ↗
- Jurnal Sain Veteriner (UGM) — Faktor Risiko Feline Panleukopenia pada Kucing di Daerah Istimewa Yogyakarta ↗
- American Kennel Club — Dehydration in Dogs: Signs, Symptoms, Treatments ↗
- PDSA — Vomiting in dogs ↗
- Puskeswan Kota Batam — Layanan ↗
- Dinas KPKP Provinsi DKI Jakarta — Dinas KPKP DKI Jakarta Luncurkan 5 Unit Mobil Klinik Hewan Keliling ↗
References can change. Check dates and context in the original source.
Cite this page
PanduanHewan. (2026, 25 September). Diarrhoea in cats and dogs: when to see a vet. PanduanHewan.org. https://panduanhewan.org/en/pet-health/diarrhoea-in-cats-and-dogs/