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My puppy has diarrhoea but is still playful. What do I do?

Written by Napo HQ
Reviewed by Dr Louisa Lane
23rd Dec 2022
7 mins read
Puppies have sensitive stomachs, and so diarrhoea can be common. Reasons for puppy diarrhoea include change in diet, stress, overeating, or infection. It is important to speak to a vet if your puppy's diarrhoea lasts more than one or two days. If your puppy has diarrhoea and vomiting together, or there is blood in their poop, you should call your vet right away. 
To help prevent puppy diarrhoea, feed a balanced and age-appropriate diet, and avoid introducing new foods too quickly.
Diarrhoea in dogs is common, but puppies are more prone than adult dogs. But when puppy poops are runnier than usual, it can be worrying. Puppy diarrhoea is often a sign that something is wrong, like an upset tummy, or a viral infection. So watching your puppy’s poop can help you keep an eye on their overall health. 
However, there are multiple causes of diarrhoea in your puppy. Our article explains the different causes of sloppy poo, what to do about it, and when to see a vet.
Being a puppy is a vulnerable time, when your pup may not yet have had all their vaccinations and their immune system is still developing. They also have sensitive stomachs, so even eating things can upset their stomach!

Why does my puppy sometimes have runny poo?

There are many reasons why puppies may experience diarrhoea. Most of these causes aren’t serious, and can be easily addressed. 
Common reasons for diarrhoea include:
  • Bacteria or viral infection
  • Dehydration
  • Dietary changes
  • Heatstroke
  • Parasites
  • Scavenging (eating something they shouldn’t)
  • Stress

Is it normal for my puppy to get diarrhoea?

Diarrhoea in puppies, and diarrhoea in dogs, are both common problems. It indicates something isn’t quite right. 
Healthy puppies will probably experience diarrhoea sometime because their immune systems aren’t fully-functioning. Puppies are, therefore, more sensitive to changes and potential sources of infection than adult dogs.
Diarrhoea typically varies from one or two mild episodes, to gastrointestinal symptoms that may indicate something more serious. Most bouts of mild diarrhoea aren’t serious and will pass within a couple of days with the right care.

What food causes diarrhoea in a puppy?

Puppies have sensitive stomachs, and food is a common source of diarrhoea. Also how they eat can cause a runny tummy.

Sudden switches

Have you changed what you’re feeding your puppy lately? Maybe your vet recommended a different type of food, or your store ran out of the usual brand. A puppy with diarrhoea may struggle to adapt if you change their diet suddenly. 
You should allow a week to ten days for any changeover in diets. 
Equally, your current food could also be the problem. Sometimes puppies develop an intolerance or sensitivity to certain foods or ingredients. 
Switching from puppy to adult food in their first year could also give your puppy diarrhoea, and that’s completely normal. 
Regardless of the reason, even a simple change in diet can cause diarrhoea in puppies. Within a few days, your puppy’s stomach should become used to the new food and the diarrhoea should stop.

Eating too much

Overfeeding your puppy can also cause loose poop because it overloads the digestive system. It is more common in younger pups but can happen at any age. 
Make sure to feed your pup according to their weight, and make any changes gradually. 

Eating something they shouldn’t

Puppies may get an upset tummy by eating something they shouldn’t. They love to scavenge, so they may pick something up on a walk or from a bin. 
Puppies also tend to beg, and it can be hard to resist. But human food scraps that are too rich for your puppy’s stomach are another possible cause of your puppy’s diarrhoea. If you can’t resist those puppy dog eyes, stick to fresh meat, vegetables, and fruit.

What can cause puppy diarrhoea apart from food?

There are many other possible causes of diarrhoea in your puppy. Diarrhoea may occur in dehydrated puppies, although vomiting is more common


It is also common in puppies who have heatstroke. Heatstroke can happen anytime if your dog gets too hot, and is often caused by exercise in warm environments. However, heatstroke is far more common in the summer months (May to September).


More severe causes of diarrhoea include bacterial or viral infection. Diarrhoea can be associated with viruses like parvovirus. 
Parvo may affect dogs of all ages but is most common in unvaccinated puppies less than a year old. Young puppies less than five months old are usually the most severely affected. 
Your vet will vaccinate against parvovirus as part of routine puppy vaccinations.


Being a puppy is a vulnerable stage of a dog’s life. Diarrhoea can be a symptom of intestinal parasites, which can be common during the first few months of your puppy’s life. 
Intestinal parasites include whipworms and hookworms, and protozoa like giardia. Although worming treatments can cause mild diarrhoea, they effectively prevent worms which can cause a much more serious bout of illness for your pup.
Bacteria like salmonella can also cause diarrhoea.


Stress is another potential cause of diarrhoea. The world is a new and challenging place for your puppy. 
You may be getting them used to spending time alone, which could cause separation anxiety. They are meeting new people all the time, getting used to walking beside traffic, and meeting other puppies and dogs. 
All of these and more can trigger stress-related diarrhoea.

Apart from the diarrhoea, my puppy still seems fine. How do I know when it’s serious?

Diarrhoea on its own isn’t a reason to panic. As we’ve explained, there may be a simple and relatively innocent reason for your puppy’s runny poo as they adjust to new food and the world around them. So, when should you be worried?
You should watch out for the signs and symptoms below:

How long has your puppy had diarrhoea?

Puppy diarrhoea can last a few hours, or persist for a few days or longer. You should talk to your vet if it lasts for longer than one or two days. Especially if your puppy has other symptoms such as lethargy and vomiting.

My puppy has diarrhoea and vomiting. What should I do? 

If your puppy has vomiting and diarrhoea together, you should call your vet. 
The cause could still be relatively mild such as dietary indiscretion (eating something they shouldn’t), which has caused mild food poisoning. 
However, this would typically last for 24-48 hours. If it lasts longer, you should call your vet. 
If your puppy seems bright and playful, the vet may advise you to monitor them at home. 
To aid recovery, your vet may recommend starvation for 12-24 hours followed by small meals of bland food such as boiled chicken and white rice. 

Should I always take my puppy to the vet when it has diarrhoea?

When your puppy experiences mild diarrhoea for a few hours, you don’t necessarily need to take them to the vet.
However, you should call your vet if the runny poo lasts more than a day, or if your puppy is showing other symptoms. 
For example, vomiting, bloody diarrhoea, lethargy, abdominal pain, bloating, and fever can be signs of parvovirus. So, call your vet if your pup has been poorly for more than a day of if they have some of these symptoms. 
You should call your vet if your puppy has not received all their vaccinations and has diarrhoea. Parvovirus causes diarrhoea in puppies and it can be deadly, so it requires immediate veterinary attention.

When should I call a vet if my puppy has diarrhoea?

 To summarise, you should call your vet if:
  • Your puppy has diarrhoea that lasts for more than a day.
  • There is blood in your puppy’s poo, or they are black.
  • Your puppy is also vomiting.
  • You know your puppy has eaten a non-food item, or a potentially toxic substance.
  • Your puppy seems lethargic or isn’t as playful as usual.
  • Your puppy stops eating and drinking.

Other frequently asked questions about puppy diarrhoea

My puppy’s stools are soft but not diarrhoea. Is that normal?

Soft poop isn’t fully formed, but not liquid. The causes of soft poop are usually the same as the causes for diarrhoea. So if your puppy has soft poo for more than a day with no sign of it firming up, or if they have any other symptoms, talk to your vet. 

My puppy’s poo is yellow or green. What does this mean? 

Green poo can often be caused by something innocent like eating a lot of grass or leafy greens. It can also mean their food isn’t staying in their long intestine long enough to digest properly, and bile isn’t being reabsorbed, which makes it a greenish hue. 
Yellow poop can also be caused by what your puppy eats. Really yellow or orange foods, like carrots, can change the colour of your pup’s poop. On the other hand, it can on rare occasion be caused by something more serious, like a liver problem.
If your pup is having poop different to the usual colour, try to remember what they’ve been eating. And if it persists, or your pup shows any other symptoms, contact your vet.

How can I stop puppy diarrhoea? 

Since dietary indiscretion is a common cause for soft or runny poop, making sure your pup doesn’t eat anything they shouldn’t is one way to stop puppy diarrhoea. Try to make sure your pup is always supervised and can’t get into the bin to scrounge.
Keeping your puppy on a complete, well-balanced diet that’s appropriate for their age, and doesn’t change suddenly, is another key way to stop runny poop and upset stomachs.

My puppy has diarrhoea. What should I feed them?

You should always ask your vet for advice before trying to change your puppy’s food, or treating them at home. 
Some puppies may need to keep eating the same complete food to prevent diarrhoea, others may need to change diets to avoid ingredients causing an intolerance, and others may need to try a bland diet for a few days.
Your vet can tell you what the best thing to feed your pup is, according to their symptoms and situation. There’s so many causes of puppy diarrhoea, there is no “one size fits all” treatment, it’ll be individual. 

When do puppies stop getting runny poo?

When your puppy will stop getting runny poop will depend on what caused it. If their diarrhoea was caused by a change in diet, or eating something they shouldn’t, it should stop within a few days. If it was caused by an infection, it might last for as long as the infection lasts plus a few days more as they recover. 
Again, there’s no “one size fits all” advice here. It depends on your puppy, and the cause of the problem. To get a clear idea of when to expect your puppy’s poop to go back to normal, ask your vet for advice.

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