What to do When Your Dog has Diarrhoea: Causes and Remedies

Dog diarrhoea is one of the most common issues dog owners face, yet it can leave you uncertain and overwhelmed. That’s why we’ve turned to the expertise of Dr Nick Thompson, an acclaimed holistic vet with more than three decades of experience helping dogs thrive through nutrition and natural remedies.

In this blog, Dr Nick dives into the possible causes behind those episodes of digestive distress, offering insights, solutions, and reassurance for you and your canine companion. Whether it’s a one-off or a recurring issue, you’ll finish reading feeling more confident and equipped to support your dog’s gut health.

From here on, Dr Nick Thompson takes over to share his expert perspective; drawing on over 30 years of clinical experience in canine health.

I define diarrhoea in dogs as: “Any time a less-than-perfect stool is seen.”

What’s a perfect stool? In my world, it looks and feels a bit like a freshly cooked sausage (meat or veggie); you can pick it up with two fingers; it leaves no smear on the ground/grass and is slightly squeezable, not rock solid.

Anything softer or more watery is some form of diarrhoea.

Let me introduce you to ‘The Thompson Stool Score’ – a simple, practical tool I’ve created to help you monitor your dog’s stools and have clearer, more accurate discussions with your vet.

Here’s how it works:

• The score runs from 0 to 10, with 10 being the ideal – a perfectly formed sausage, as described earlier.

• A 0 represents a brown liquid soup – not what we want to see.

• A 5 out of 10 is a softer consistency, similar to chocolate blancmange.

• If your dog is slightly constipated, chalky stools can push the score up to 11 or 12.

I never grade beyond 12, but this scale is a straightforward way to assess stool quality and support your dog’s gut health.

The perfect stool is not very odorous. If a stool at any score is really foul, it suggests that digestion and gut health may be compromised. You can add to the three dimensions of the score by noting blood, pain, mucus, or a change of colour in the stool.

The important thing is to remember the 0-10 score is the backbone of the system. Don’t make it any more complicated than it needs to be!

If, like all dogs, the stool drops on the scale from a 9-10 to a 3, 4,5 or 6, for example, but only for a few days, before normalising, this is known as acute (short-lasting) diarrhoea. It’s common and usually does not cause the dog any injury/discomfort.

Chronic (from the Greek for time, Chronos) Diarrhoea is where stool quality is permanently poor – say below a 7 or 8 all or most of the time. If your dog has chronic Diarrhoea (for more than two weeks), then you’ll need some help from a vet, a raw food company, a raw store, or a nutritionist. If you have any significant worries for your dog, please initially play it safe and see your local vet.

Dogs often eat rubbish. Sorry, but that’s just the way it is. Vets call this dietary indiscretion. It is the most common cause of mild or moderate acute diarrhoea. We’ll discuss what to do with this in the next section.

Some dogs don’t go raiding the bins next door or go take-away hunting in the park, yet still get ‘runny tummies’ periodically. These dogs may have food sensitivities.

Typically, an owner will tell me that the dog gets short-lasting diarrhoea randomly during the month for no good reason. Most of my clients feed a good range of raw food, so in this case, sensitivities to particular proteins can be the cause.

Let’s say your dog has a sensitivity to chicken meat. It means that whenever chicken is fed, knowingly or unknowingly, the gut might be affected and a short stint of diarrhoea might be the result. When the chicken food is removed, the diarrhoea disappears.

Some of the culprits in the example above are treats that contain chicken, but it’s not obvious until you read the ingredients. Also, some manufacturers will use chicken but will not declare it obviously on the front of the pack.

When vets, on the other hand, think about the causes of diarrhoea, we have a long list that we divide into sections. Let’s have a look at those sections right here:

Genetics: Inherited conditions can predispose certain breeds to specific diseases. For example, Histiocytic ulcerative colitis (HUC) is a disease associated with infection with E. coli (atypical adherent and invasive E. coli, AIEC) that affects Boxers, French bulldogs, Mastiffs, Alaskan malamutes, and Dobermann pinschers [1].

Another interesting one is German Shepherd Enteropathies. With an inherited predisposition to exocrine pancreatic insufficiency (EPI), German shepherd dogs (GSDs) are prone to chronic gut issues. EPI is not strictly a GI disease, but heritability has been displayed in Rough collies as well as GSDs, and surveys have shown that these breeds, as well as the Chow Chow and Cavalier King Charles spaniel, are clearly predisposed to EPI [2].

Infections: Bacterial, viral, fungal, and parasitic infections can cause various gut diseases. These can appear spontaneous but are usually associated with eating contaminated food, soil, water or sticks in the environment. However, considering the amount of rubbish most dogs eat daily as they scavenge down the lane or in the bushes in the park, gut upsets are not half as common as you’d expect! If you ate what the average labrador ate and scavenged in a week, you’d be as sick as a dog!

Organ function: if your mouth isn’t producing enough saliva, your stomach has insufficient or too much acid, your pancreas has too little digestive enzyme, or your gut is not producing enough mucus or motility to massage food from one end to the next of the gastrointestinal tract, your digestion will suffer. It’s the same with dogs. With all the complexity of the body’s systems, it’s a wonder any of us can digest anything at all. Yet we, and our dogs, pull off this daily miracle without a second thought. But when just one part of the system isn’t working properly, the whole process can suffer.

Environmental factors: Exposure to toxins such as glyphosate in Europe and the USA, Atrazine in America, or other pollutants can cause damage to the gut or the microbiome, leading to diarrhoea, Leaky Gut disease or IBD (Inflammatory Bowel Disease). Extreme heat or cold conditions can impact health, too.

Microplastics are now found in many human foods, air, and water. People consume an estimated 78,000 to 211,000 microplastic particles each year through food, drink, and breathing. This is considered an underestimate. A Study by the University of Newcastle, Australia, in 2019 study commissioned by the World Wide Fund of Nature (WWF) found that people consume about 5 grams of microplastics every one to two weeks, roughly the same as the weight of a credit card during the same period! This is equivalent to about 250 grams of plastic per year. I imagine our dogs are consuming roughly the same. [3].

Other factors, too numerous to mention, include age, lifestyle, stress, vaccination status, hormonal disease, neutering and parasites can disrupt balanced gut function. This is why we suggest if you are in any doubt as to why your dog has diarrhoea, or the dog is in any distress, get along to your local vets.

Ok – it’s Sunday morning, and you wake up to a small brown sea of 1/10 diarrhoea in the middle of the kitchen floor. Joy.

First thing:, how is the dog? If your dog has diarrhoea but is acting fine, if they are bright and well and are still up for their morning walk, then great. Continue your morning as normal (but feed the lightest meats you have available for a few days). Hopefully, you’re feeding raw. The benefits of raw feeding dogs are numerous, but even if you’re not, going for the chicken, turkey, lamb tripe or white fish dishes of this world is a good idea until things resolve with your otherwise normal dog. Avoid rice. I use lightly steamed greens instead. Sometimes I’ll use cooked quinoa, amaranth or buckwheat.

If you come down to diarrhoea and your dog is dull, especially if they’re a puppy, then it’s a trip to the vet, I’m afraid. They might just give the dog a check-over, assess hydration and send you home with some electrolytes. Fine. Try to avoid antibiotics if at all possible.

If the dog is dehydrated and really not doing well, they’ll likely take them in, put them on a drip to hydrate and give appropriate meds, including, often, antibiotics. For example, they might take a stool sample to check for infection with E.col, Salmonella or Clostridial bugs. It’s worth discussing giardia or coccidiosis, too. These are essential tests if the diarrhoea is chronic, but less so with acute cases.

If your dog has had yet another bout of squits, you might be in chronic diarrhoea territory. Therefore, it’s a trip to the vet in the next few days to get a ‘chronic diarrhoea workup’ to eliminate causes of long-standing diarrhoea.

Rest and recovery are important when you get home from the vet with your acute diarrhoeic dog. You might want to feed the dog little and often, say, 3-4 times a day with smaller meals. Do not over-exercise the recovering dog. Think about using bone broth for dogs to encourage hydration. Probiotics are also great for the recovering dog.

Diet and supplements are critical to managing acute and chronic diarrhoea. With acute diarrhoea, all you need to do is feed the blandest diet you’ve got available for a few days (and consider bone broths and pre- and pro-biotics), and most dogs will heal themselves.

If you have a dog with chronic digestive issues, then a diet review is even more important, especially as your dog may have sensitivities to certain foods. If you suspect this to be the case, talk to your raw vet, your own vet or a nutritional advisor, who may recommend an elimination diet. There are no reliable tests, even blood or saliva tests, for which foods (mainly proteins) do and don’t suit your dog.

I cannot overemphasise the value of feeding raw dog food. We see far fewer digestive upsets, either acute or chronic, for dogs on this type of natural whole-food diet. Raw diets are highly digestible, very tasty, and innately probiotic. Most contain connective tissue and collagen, which is nature’s fibre source for carnivores. So important.

Transitioning to a raw diet is easy. There are various simple methods. The easiest for a healthy dog with a good gut is to just change overnight from kibble and cans to raw. The next method is similar. You just take a few days to transition from ultra-processed to raw.

If you want a halfway house, try the ‘doubling method’. Here’s how it works: Start by adding one teaspoon to the bowl on the first day. On the second day, add two. On the third day, add FOUR, eight, then keep doubling until you’re fully over onto the new food. It’s a way of ensuring you start small but move forward more rapidly.

Talk to your raw food manufacturer or your local raw store for guidance. The team at ProDog Raw have put together this helpful guide, How to Switch to Raw, packed with advice to make the transition simple and stress-free. It’s an ideal place to start.

Dehydration is the major threat with intense acute (mainly) or chronic diarrhoea, especially with small dogs and puppies. Diarrhoea contains a lot more water than normal stool. Therefore, the body loses more water than it normally would. An important job of the colon is to take water from the digested material to conserve water in the body.

The major sign of diarrhoea is malaise due to dehydration. If you’re dehydrated, you just don’t feel like doing anything and may be irritable and off your food. It’s the same for dogs.

Physically, it’s possible to gently pinch the skin over the ridge of bone above the eye. In the normally hydrated dog, the skin pings back into place immediately. The more delayed the pingback, the more dehydrated the dog is. If in any doubt, get the dog checked at the vets.

It’s worth encouraging the diarrhoeic dog to drink. This is easier said than done! Adding some bone broth to the water is the best way to keep a dog hydrated. Always offer clean water as well as any alternatives. Alternatively, you can offer two bowls of water, one with ½ tsp salt per pint and the other with clean water. Raw foods or any sloppy foods are another good way to hydrate, but nothing beats good old water or bone broth.

Digestive support foods for dogs with diarrhoea

What are the best foods for your dog with diarrhoea? Those foods that you know work best for their gut! Some dogs do better on venison, some chicken, some turkey. If you always have a few packs of your ‘go-to’ protein source in the freezer, that’s your emergency rations. Very handy.

Products containing prebiotics like marshmallow root, aloe vera and slippery elm help soothe the gut and feed the good bugs. The world of science is trending away from probiotics and more in favour of prebiotics, but I still think probiotics can be useful. It’s worth talking to your raw food supplier or raw store to see what powder, capsule or dog probiotic paste they carry. Healthy dogs don’t need pre or probiotics continually, but if they have diarrhoea, they often do.

Herbs and supplements to aid recovery from diarrhoea

Herbs such as marshmallow, aloe vera and slippery elm – are all fantastic for reducing inflammation in the gut. But also consider Chamomile, Fennel, , Chia seeds and ground pumpkin. These powdered herbs replicate the gut contents of herbivores—exactly what carnivorous dogs have naturally consumed for millions of years by eating their prey, organs and all!

Also, consider herbs and supplements like liquorice root, chlorella, psyllium husk and parsley.

Digestive enzymes are safe to use in most situations, even in pups or pregnant bitches. They help break down foods in the gut – especially useful if gut transit time is fast, as we see in diarrhoea. Digestive enzymes are also helpful if there are signs of canine pancreatitis (vomiting, malaise, continual stretching) where the pancreas may not produce sufficient digestive enzymes for a while.

For a deeper dive into pancreatitis, read this blog, Pancreatitis in Dogs, written by Canine Nutritionist Alison Frost, with insights from yours truly!

Finally, on the topic of supplements, ProDog’s Digest powdered supplement is an excellent choice for a digestive supplement for dogs, packed with many of the gut-supporting herbs and prebiotic ingredients mentioned above. Be sure to check it out. Also, if you feel you’d benefit from tailored advice, ProDog’s Nutrition team is always on hand to provide 1-1 support—don’t hesitate to drop them a line.

Ok, so we’ve got our doggo over the acute or the chronic diarrhoea. How do we keep it that way? It’s impossible to prevent any upset for life, but if we can make the gut and gut biome more robust and less inflamed, it will then be much better equipped to handle the slings and arrows of everyday life.

To keep a dog’s gut healthy, feed the best raw dog food you can find – food that works for your dog’s gut to keep them routinely in the 9 and 10s on the stool score. If your dog has excellent poos in the morning but less solid in the afternoon after zooming about the woods or the park, consider using Colostrum.

Several studies have highlighted the improvement in faecal quality when bovine colostrum is included in a dog’s diet. A 2013 study examining the immune-supporting properties of colostrum reported improvements in gut health markers [4].

More recently, a 2023 review pulled together the existing data on colostrum’s impact on both canine and human gut health. This review reinforced its benefits for faecal quality, citing mechanisms such as reduced gut permeability and improved function of the gut-associated lymphoid tissue (GALT)—both of which contribute to healthier, more consistent stools [5].

A consistent routine is a good idea when feeding dogs, but avoid feeding the same protein for months and months. Dogs fed the same meal daily for long stretches are at risk of nutrient deficiency – a problem that variety feeding protects against. You can use different brands, or, more conveniently, stick with the same brand, but use different options on offer.

I also recommend avoiding feeding the dogs at the same time every day. This helps us be more flexible when we need to be around other life stuff like children, work,etc. Plus, it means the chance of ‘hunger pukes’ half an hour before mealtime is reduced.

An annual check-up with your local raw-friendly vet practice is a good idea, just as visiting the dentist is a good way for us to catch issues early. Also, I always advise my clients to avoid oral and even drop-on pesticide products for fleas and ticks where possible. Similarly, I use routine worm counts of stool samples sent away to avoid the routine use of pharmaceutical wormers. All drugs that impact your dog, whether oral or drop-on, will impact the all-important microbiome.

I find that once an owner’s been through a bout of diarrhoea with their dog, they tend to be very attentive to the quality of the stools. It’s definitely worth it to know what’s normal for your dog and make changes if you see a departure from a really good, normal 9-10 out of 10 poo score.

A holistic approach to managing diarrhoea in dogs

So, there you have it, a beginner’s guide to managing diarrhoea in dogs. All dogs get a bit loose from time to time. That’s fine. But if they have a bad acute or drift into chronic diarrhoea, you’ll have a little more understanding now. I think the most important thing is to learn what works for your dog and keep a close eye on all aspects of digestion without getting too paranoid.

I also encourage clients to read as widely as possible books, blogs, podcasts and articles that discuss digestion – human or canine – to learn about the incredible infinite machine that is the gut and the biome. And, like I said, the team at ProDog are always happy to help! So, if you have any questions or need some advice about your dog’s diet, just drop them a line.