Dog and Cat Diarrhoea: What to Do, When to Worry, and When to See Your Vet
- Apr 20
- 7 min read
By Nicola Roberts, Registered Veterinary Nurse
From mild tummy upsets to more persistent or recurring concerns, diarrhoea is something most pet owners will encounter at some point.
One of the most common things we hear is:
“They seem fine in themselves… should I still be worried?”
Sometimes it settles quickly on its own. Other times, it lingers or comes and goes, leaving you unsure whether to wait, try something at home, or seek advice.
If your dog or cat has diarrhoea, it’s completely natural to feel uncertain. You might be wondering:
Should I change their food? Should I wait? Should I stop feeding altogether?
In this guide, we’ll gently walk you through what’s normal, what’s not, and how best to support your pet, so you can feel confident in knowing when to act.
Contents
What counts as diarrhoea in dogs and cats
What Counts as Diarrhoea in Dogs and Cats?
Diarrhoea doesn’t always mean very watery stools. In fact, many cases are more subtle.
It can include:
Softer than normal stools
Going more frequently than usual
Urgency or needing to go quickly
Accidents in the house
Mucus or a jelly-like coating
Fresh blood or darker stools
A single soft stool is often not a concern if your pet is otherwise bright and well.
However, ongoing or repeated changes are worth paying attention to.
If something has changed and isn’t settling, it’s always worth noticing.
And you’re certainly not alone in wondering what’s normal. Thanks to our practice PetsApp, we’re regularly sent photos of poo so we can help guide owners. It might feel a little unusual, but it’s genuinely helpful, and always okay to ask.
What If There’s Blood in the Poo?
Seeing blood in your pet’s poo can be worrying, and it’s something we’re often asked about.
Not all blood is the same, and the appearance can give us helpful clues.
You might notice:
Fresh, bright red blood
This is often linked to irritation in the lower part of the gut, such as with diarrhoea or straining. It can look dramatic, but is not always as serious as it appears.
Darker, black or tar-like poo
This can indicate bleeding higher up in the digestive tract and is something we would want to assess more urgently.
In many cases, a small amount of fresh blood alongside diarrhoea can occur with inflammation of the gut.
However:
👉 If you’re seeing more than a small amount, if it continues, or if your pet seems unwell, it’s always best to have them checked.
Common Causes in Dogs and Cats
There are many possible causes of diarrhoea, and often it’s something mild and short-lived.
Common reasons include:
Eating something unusual (scavenging)
Sudden changes in diet
Stress or changes in routine
Parasites
Infections
Food sensitivities
It’s also worth mentioning that some dogs will eat faeces, either their own or from other animals.
This behaviour, known as coprophagia, is quite common and can introduce bacteria and parasites into the gut, sometimes leading to diarrhoea or ongoing digestive upset.
Intermittent Diarrhoea: Why It Matters
One of the more confusing patterns we see is intermittent diarrhoea, where stools improve and then return again days or weeks later.
A really common scenario is:
A mild upset
Things seem to settle
Then it happens again
Your pet may seem completely normal in between, which can make it easy to assume everything is fine.
If there’s one thing to take away, it’s this:
👉 Diarrhoea that keeps coming back is always worth investigating.
Common causes include:
Parasites that are not shed all the time
Food sensitivities or intolerances
Ongoing gut imbalance after a previous upset
Low-grade inflammation in the digestive tract
Early investigation can make a big difference and often prevents things becoming more prolonged or frustrating.
Should You Feed a Bland Diet?
You may have heard that feeding boiled chicken and rice can help.
While this can be useful short-term, it isn’t always the most effective option.
Chicken and Rice: Myth vs Reality
Myth:
Chicken and rice is always the best thing to feed when your pet has diarrhoea.
Reality:
While it can help in some mild cases, it’s not always the most effective option, and in some pets, it can actually slow recovery or lead to ongoing soft stools.
This is because:
It isn’t nutritionally complete
It doesn’t actively support gut healing
Some pets don’t tolerate rice well
It may not address the underlying cause
In many cases, a veterinary gastrointestinal diet is a better option, as it is specifically designed to support digestion and recovery.
For cats, it’s always best to seek advice before making dietary changes.
Should You Stop Feeding?
It used to be common advice to “starve” pets for 24 hours when they had diarrhoea.
We now know that this is not usually helpful, and in many cases, it can actually slow recovery.
The gut relies on nutrition to:
Maintain the lining of the intestines
Support healing
Keep the balance of healthy bacteria stable
Instead of stopping food completely, it’s usually better to:
Offer small, frequent meals
Use a highly digestible diet
Keep things gentle and consistent
There are some exceptions where short-term fasting may be advised, but this is best guided by your vet.
What You Can Do at Home
If your pet is otherwise well, bright, and eating, there are some simple steps you can take:
Keep fresh water available at all times
Offer small, frequent meals
Stick to simple, digestible food
Avoid treats, chews, or rich foods
Keep their routine calm and consistent
Just as importantly, look at the bigger picture.
Often, how your pet is behaving overall is just as important as the diarrhoea itself:
Bright, eating, and active → often less urgent
Quiet, off food, or withdrawn → more concerning
Signs of Dehydration to Watch For
One of the main risks with diarrhoea is dehydration, particularly in young or older pets.
Signs to look out for include:
Drinking less or more than usual
Dry or sticky gums
Lethargy or weakness
Sunken eyes (in more advanced cases)
If you notice any of these signs, it’s best to seek advice sooner.
When to Contact Your Vet
You don’t need to wait until things feel serious.
Contact your vet if you notice:
Diarrhoea lasting more than 24–48 hours
Blood in the stool
Lethargy or reduced energy
Vomiting
Loss of appetite
Intermittent or recurring diarrhoea
It’s especially important to seek advice sooner if your pet is very young or older.
Puppies, kittens, and elderly pets can become dehydrated more quickly and may have less resilience to cope with even mild diarrhoea.
How Quickly Should Your Pet Be Seen?
Same day (urgent):
Lethargy or weakness
Repeated vomiting
Significant blood in the stool
Signs of abdominal pain
Diarrhoea in very young or elderly pets, especially if they seem even slightly unwell
Within 24–48 hours:
Not improving
Eating less
Ongoing or intermittent diarrhoea
If you’re unsure, a quick call can help guide you.
How Diarrhoea Is Treated
Treatment depends on the underlying cause, but is usually focused on supporting the gut and helping your pet feel more comfortable.
This may include:
Gut-supporting medication
Dietary support
Parasite treatment
Further investigations if needed
Early support often leads to a quicker, smoother recovery.
A Note on Antibiotics
It’s very understandable to think antibiotics might be needed when your pet has diarrhoea.
However, in most cases, they are not the right first step.
This is because:
Most diarrhoea is not caused by bacteria needing antibiotics
Antibiotics can disrupt healthy gut bacteria
This can sometimes delay recovery
Instead, treatment is usually focused on helping the gut recover naturally.
There are situations where antibiotics are needed, but this is always based on your pet’s individual signs and, where needed, further testing.
The Role of Probiotics and Faecal Testing
Probiotics
Probiotics help support the natural balance of bacteria in the gut and can:
Improve stool consistency
Support recovery
Reduce recurrence
Faecal Testing
For ongoing or intermittent diarrhoea, faecal testing can be very helpful.
We often recommend a 3-day pooled sample, as some parasites are only shed intermittently.
This means:
A single sample may miss the cause
Multiple samples improve accuracy
Faecal testing can be an investment, and while it might feel easier to bring in just one sample, this can reduce accuracy.
If the problem is missed, this may lead to:
Repeat testing
More appointments
More cost overall
Taking a little extra time to collect samples properly helps us get the most reliable answer first time, which is often more cost-effective in the long run.
It’s also worth knowing that including faecal testing as part of your pet’s annual wellness care can be a really valuable way of picking up parasites or subtle gut changes early, often before symptoms develop.
Preventing Future Episodes
While not all diarrhoea can be prevented, small, consistent steps can make a big difference over time.
These include:
Keeping your pet’s diet consistent
Introducing new foods gradually
Maintaining regular parasite prevention
Being mindful of scavenging or eating poo
Reducing stress where possible
Supporting gut health isn’t just about treating problems when they arise, but helping maintain balance over time.
Routine health checks can play an important role here, and including faecal testing as part of your pet’s annual wellness care can help pick up parasites or subtle gut changes early, often before symptoms become obvious.
This allows us to treat issues sooner, helping keep your pet comfortable and reducing the likelihood of ongoing or recurring problems.
Final Thoughts
Diarrhoea is common, and many cases settle quickly.
But if it lingers, returns, or doesn’t feel quite right, it’s always worth checking.
You’re never wasting our time by asking.
We would always rather help early than see things become more uncomfortable for your pet.
And even when everything seems normal, staying on top of preventative care and routine checks can offer real peace of mind and help catch small changes early.
.png)
