If you own a dog, chances are you’ve dealt with poop on a regular basis. If you’re reading this post, you’ve probably recently found yourself in the position of cleaning up dog poo that’s lacking in structural integrity. So, you now find yourself asking, “why is my dog’s poo runny?”

What causes my dog’s poo to be runny?


an illustration of a large, sloppy poo

Your dog’s diet can play a big role in why their poo may be runny. Dogs that are fed processed and high carbohydrate diets commonly have stools that are large and sloppy. Processed dog food often includes fillers, artificial flavours, and additives that disrupt dog's digestive systems. High carbohydrate diets have been found to negatively affect the overall health of dogs, leading to obesity, allergies, infections, and even cancer. Therefore, it is crucial to calculate your pups' carbohydrate needs to ensure they are eating a balanced diet while keeping their poos at optimum consistency. You can use our commercial dog food carbohydrate calculator if your pup doesn’t eat Big Dog.

Quick change in diet  

an illustration of runny diarrhoea poo

A sudden change in diet can also be a cause of diarrhoea, as the quick change can upset your pup’s tummy and intestinal tract. So, it's important to gradually change their diet by slowly increasing their new diet while decreasing the current diet over two weeks. If you are switching to a raw diet, check out our handy guide for transitioning your dog to raw food.

Benefits of feeding your dog a raw diet

an illustration of a cattle dog sitting with bowl of raw food, happy and patiently waiting to eat

Raw food diets are found to significantly aid in the consistency of your dog’s poo, as more of the natural food and good nutrients are absorbed in the digestive system, so less comes out the other end.

Other benefits of raw dog food include:

  • Superior joint and bone health
  • Strengthened immune system
  • Improved skin and coat
  • Superior dental health
  • Enhanced reproductive health
  • Reduced body odour

To learn more on the benefits of feeding your dog a raw diet, check out this article. At Big Dog, we offer a vast range of raw dog food with various flavours offering maximum nutrition to keep all breeds happy and healthy.


an illustration of watery diarrhoea poo

If your dog has recently gone through a stressful event, such as moving house, recently visited the vet or had an operation, they may have developed ‘stress colitis’. One of the most common symptoms of stress colitis is watery diarrhoea, which is important to monitor closely and have fresh water readily available as it can lead to dehydration.

If your dog is an adult, it is recommended to fast them for 6 to 12 hours to allow their gut to rest and heal. If you have a puppy, it is not recommended to fast as they are growing, so it is best to seek advice from a vet.

You can also feed your dog a probiotic that helps with anxiety, such as our Stress & Anxiety Probiotic, which is designed to support the immune system and reduce inflammation in the gut. If the watery diarrhoea persists for more than 12 hours seek veterinary advice.


an illustration of poo that starts solid and finishes runny, a potential sign of IBS

Poos that consist of both soft and firm parts can be an indicator of irritable bowel syndrome, otherwise known as IBS. If this is the case, it is best to consult with your vet to get a proper diagnosis.

Dogs with IBS are found to benefit from probiotics, as they assist with the symptomatic relief of digestive issues like diarrhoea. At Big Dog, we offer a Soothe and Support Probiotic designed to support digestive health and reduce the instances of leaky gut.

My dog has diarrhoea but is acting fine  

In some cases, your dog can be acting fine even when they have diarrhoea. So here are some common reasons if this is the case:

  • Recently started a new medication
  • Less severe bacterial or viral infections
  • Ingestion of a foreign object, spoiled food, or plants

If you are at all concerned or the diarrhoea persists for more than 12 hours, it is best to consult with your vet.

Dog poop chart  

On our handy Dog Poo Chart, take note of the consistency score to see what your dog’s poo is currently telling you and what the ideal poo should be (score 2 or 3). You can print out our poo chart to have it readily available when you check your dog’s poo.  

Click above image to download Poo Chart PDF

It’s important to remember that not all runny poos mean something more serious is going on. As mentioned, if you are ever concerned about the consistency of your dog’s poo, it is best to consult with your vet.