Cat diarrhoea – when should I see a vet?

Updated 2026-09-30 · 2 sources

Based on: PDSA, International Cat Care (iCatCare)

Book a vet visit

This is not usually an emergency on its own – contact your vet if it lasts, gets worse or your cat seems unwell in any other way. It can follow a sudden change in diet or eating something that upsets their tummy.

When to contact a vet What to do now

Contact a vet if you see any of this

Diarrhoea that has not improved within 24 hours
Diarrhoea that gets worse
Vomiting
Lethargy or low energy
Blood or mucus in the poo
A painful abdomen

What you can do now

Contact your vet if you are concerned
Note when it started, how often it happens and what else you see
Take a photo or short video to show the vet
Keep fresh water available
Let your cat rest somewhere calm

Don't

Do not give any human medicine
Do not wait if it gets worse

What it can mean

Diarrhoea can mean your cat is passing soft, liquid or watery stools, or stools that are lighter or darker than usual.^[2] It can be linked to a sudden change in diet, something that upsets the tummy, worms, gut parasites, pancreatitis, gut infections, viruses or poisoning or toxins.^[1] There are many potential causes, so your vet may need to investigate to find the underlying problem.^[2]

Other signs that can come with it

Straining to pass faeces
Passing faeces more often than normal
A dirty, smelly or sometimes painful bottom
Gurgling stomach noises
Farting more than usual
A bloated tummy
Excessively cleaning their bottom
An unkempt coat

Possible causes

A sudden change in diet
Eating something that upsets their tummy
Worms
Gut parasites such as giardia, cryptosporidium and tritrichomonas
Pancreatitis
Gut infections such as Salmonella and Campylobacter
Viruses such as Feline Panleucopenia Virus
Poisoning or toxins

What the experts say

“Going outside more regularly than usual ; A dirty, smelly, sometimes painful bottom ; Gurgling stomach noises ; Farting more than usual ; A bloated tummy ; Excessively cleaning their bottom ; Lethargy (low energy) ; An unkempt coat”
— PDSA [1]

“Treatment of diarrhoea can be either specific or supportive. Most cases of moderate to severe diarrhoea will need some form of supportive treatment but specific treatment means identifying the underlying cause and targeting the treatment at this.”
— International Cat Care (iCatCare) [2]

If your pet is struggling to breathe, has collapsed, is having a seizure or can't stand up: go to the nearest vet now.

Not sure how serious it is?

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Common questions

What does normal cat poo look like?

Normal, healthy cat faeces are brown, firm and well-formed.^[1]^[2]

What can cause diarrhoea in cats?

Possible causes include a sudden change in diet, eating something that upsets the tummy, worms, gut parasites, pancreatitis, gut infections, viruses and poisoning or toxins.^[1]

What will the vet do?

Your vet will take a detailed history from you and examine your cat before deciding whether any further tests are needed.^[2]

Sources

How this page was made: written with the help of AI from the sources below, then checked claim by claim against those sources. Urgency levels follow OkPaw’s fixed safety rules. It is guidance, not a diagnosis. How we write our pages

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