We’ve all had that panic. Come into the lounge room, and there is a scent lingering in the air. You know what you’re about to find, you just have everything crossed that it's not spread too widely.
What can cause your dog to have diarrhoea, what can you do about it, and what happens if it becomes a regular problem?
What causes diarrhoea in dogs?
Dogs can be sensitive souls, and a whole range of things can cause digestive upset, resulting in loose stools or full-blown diarrhoea. Here are just some of the things that can cause diarrhoea in dogs.
Dogs with dietary sensitivities
Not just allergies, but also intolerances to ingredients in their diet can upset their gut.
Stress in dogs
Changes to your dog’s routine—new animals in the house, lots of people, trips to new places, DIY. Dogs are sensitive to stress, and this can often show up in their stools as diarrhoea.
Dogs on antibiotics
Antibiotics are designed to kill bacteria, but they don’t just kill the problem microbes, they will also reduce the number of good bacteria, causing an imbalance in your dog’s gut microbiome. This regularly results in diarrhoea, and has even been shown to make dogs more likely to need further antibiotics.
Medication for dogs
If your dog is on medication for other issues, it can unbalance their digestive system and disrupt the microbiome balance. This is particularly important for those dogs taking steroids or NSAIDs (anti-inflammatories).
Diet changes for dogs
A consistent diet results in consistent stools. Any changes you make to your dog's food need to be made slowly so as not to disrupt their digestive system.
Canine infections or parasites
Both infections and parasite infestations, such as worms, will impact your dog’s digestive system, often resulting in diarrhoea.
Dogs that scavenge and steal food
Whether they’re stealing food from you or snaffling down possum poo while they’re out, these random additions to their diet can cause upset to your dog’s digestive system.
Poisoning
This one is a major concern and needs to be seen by a vet. Any concerns that your dog may have been poisoned will need immediate attention. You can also seek advice from the Animal Poisons Helpline on 1300 869 738.
Other Signs That Come With Dog Diarrhoea
Often, canine diarrhoea can show up as the only symptom your dog experiences, but there are other things to look out for if your dog is struggling with diarrhoea.
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Vomiting
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Blood in stools
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Gas
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Lethargy
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Mucus in stools
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Appetite changes.
Why does my dog have diarrhoea but seems fine in themselves?
Diarrhoea in dogs is often a short-term, acute problem. Mild digestive upset, perhaps caused by stealing food, or even long-term or low-level gut imbalance, can come with very few other symptoms—it’s often localised just to the digestive system. Diarrhoea can be a self-limiting issue and is a sign that your dog is managing the issue themselves. However, it’s important to always keep a close watch on them, as diarrhoea can rapidly develop and cause issues such as dehydration, which will need immediate support.
Chronic vs acute diarrhoea in dogs
Chronic diarrhoea is a long-term condition, with loose, watery stools that persist for two or more weeks, or are intermittent over a period of a month or more.
Acute diarrhoea in dogs is a much shorter-term issue; it often comes on quickly and can be self-limiting during a period of infection or infestation.
Both may require veterinary attention, but will need different management.
If your dog has long-term gastrointestinal upset or intermittent periods of diarrhoea, it is worth considering long-term gastrointestinal support, with a product like Symbiol, alongside any recommended treatments from your vet. This will support their gut over a long period.
Can poor gut health cause diarrhoea in dogs?
The gut contains an entire ecosystem known as the gut microbiome. The flora (all the microbes) in the gut are in a delicate balance. This balance in a healthy gut has more beneficial bacteria than pathogenic (or bad) bacteria. In an unbalanced gut, the balance skews more towards the negative. In the long term, this can lead to low-level gut disturbance, such as soft stools or gas. A rapid, or major change to the gut flora can also cause a flare in diarrhoea symptoms.
Can probiotics help with dogs with diarrhoea?
Probiotics are live bacteria that you can feed directly to your dog to help colonise their gut with beneficial microbes, helping to rebalance the microbiome if it is disturbed. But their effectiveness depends on the strains of microbes within the supplement, as well as whether your dog is also on other medications, in particular antibiotics.
Many strains of probiotics won’t survive transport through the stomach acid, or will be killed by antibiotics, so ensuring the right strains, such as Bacillus subtilis and Bacillus claussi will give your dog’s gut the best chance at rebalancing.
But it's not just probiotics that are important in your dog's gut health. When choosing a supplement, you should consider ingredients that help to fuel your dog's gut microbes and support the cells lining the gut. A strong gut barrier, combined with a healthy, balanced gut microbiome, is key to firm stools and a healthy gut.
Learn more about probiotics for dogs here.
When should you see your vet about your dog’s diarrhoea?
If you notice any changes to your dog’s stools, it is always advisable to speak to your vet, who can then suggest further action. However, these are some signs which will always need veterinary attention:
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Blood in the stools
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Lethargy
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Persistent diarrhoea
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Stool changes in puppies
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Dehydration
We always recommend talking to your vet if you have any concerns about your dog’s health.
How does the Symbiol™ range support your dog with diarrhoea?
Whether it's long-term support for those sensitive dogs, or when your dog’s gut needs rapid support, the Symbiol™ range is there for your dog.
Symbiol™ Daily Gut Balance - For dogs' daily gut health, healthy stools and less gas.
Dogs show us when something’s not quite right—from loose stools and sensitivities to changes in energy, coat, and overall wellbeing. Because gut health isn’t just about digestion. When it’s out of balance, it can affect how your dog feels every day.
Symbiol™ Daily Gut Balance is a science-backed, multi-action supplement designed for everyday use to support gut health from the inside out. Going beyond basic probiotics, it combines resilient Bacillus strains, an advanced New Zealand Honeydew Honey prebiotic, and targeted nutrients to help stabilise the microbiome, strengthen the gut lining, and support digestion—creating a more balanced and resilient gut, for long-term health.
Visible results, every day:
Healthy stools. Digestive comfort. A dog that’s comfortable and thriving.
Symbiol™ 14-Day Gut Protocol - Digestive care during antibiotic use
Symbiol™ 14-Day Gut Protocol is support when dogs need it most.
Acute illness and medical interventions—including antibiotics, NSAIDs, corticosteroids, and surgery—can significantly disrupt the gut, triggering microbiome collapse, gut lining damage, and reduced appetite (Suchodolski, J.S., 2016). This can directly affect how well dogs recover and how they feel during and after treatment.
During these periods, your dog’s gut doesn’t just need support - it needs a reset.
Generic probiotics and fibre-based supplements often fall short in this critical window. Many do not survive alongside antibiotics or address the full scope of gut disruption, leaving a gap in care when dogs are most vulnerable.
As part of the Vetz Petz® Inflammation Support Range, Symbiol™ 14-Day Gut Protocol is designed specifically for this critical recovery window.
It combines antibiotic-resilient Bacillus clausii to help repopulate the microbiome during treatment, NZ Colostrum to support immune and mucosal repair, and targeted nutrients to help protect the gut lining, restore hydration, and support digestive recovery.
The result?
Improved stool quality, restored appetite, better hydration, and a faster return to overall well-being—helping your dog feel more like themselves again during and after antibiotic use.
Symbiol™ is coming - Get on the waitlist!
Does your dog’s gut need some TLC? Join the waitlist here to be one of the first to get your paws on advanced support for your dog’s gut.
