Dealing with dog diarrhoea

Vets CornerDiarrhoea in dogs is such a common problem it’s usually not a case of if it will happen, but rather when it will happen. Here Paul Boland looks at what can cause it, how to tackle it and what you can do to prevent it in the latest of our Vet’s Corner series…

Diarrhoea is the passage of loose, unformed faeces. Initially there is normally a large volume of stool and an increased number of bowel movements. In the normal process of digestion, food would normally take about eight hours to pass through the small intestines. During this time, the bulk of the food and 80% of the water would be absorbed. Whatever is left makes its way to the colon and a well-formed stool is deposited. A normal stool contains no mucus, blood, or undigested food.

With diarrhoea, food arrives at the rectum in a liquid state which results in a loose, unformed bowel movement. This type of rapid transit accounts for the majority of temporary diarrhoea in dogs.

Because diarrhoea can happen at any time and can take effect very quickly it would be a good idea to be prepared for when it does happen. Although many people are doing many of the right things when these occurrences happen I think it’s always good to have a refresher on the best way to treat diarrhoea.

After all it can be one of the most unpleasant of experiences to have for both you, your family and your dog.

What causes diarrhoea?

There are a huge range of reasons a dog may develop diarrhoea however the most common is something it’s eaten. This is especially true over holiday periods when you may be hosting family gatherings and cooking, richer fattier or even new foods. Although I never recommend giving human foods to dogs invariably many dogs will eat some of this food. Mostly because the owner will give it to them as a treat. Even if this isn’t the case dogs have an amazing capacity to acquire some of this tasty food without their owners even knowing. It’s very common for dogs to eat dropped food and not uncommon for them to rummage around in bin bags once the food has been disposed of. These leftovers or treats can and do cause many GI complaints

I have seen many dogs who also love to eat and drink from bird feeders, ponds, bird baths and muddy pools. Dogs will naturally scavenge and tend to eat many unusual indigestible substances, dead animals, grass, wild and ornamental plants, and pieces of plastic, wood, paper, and other foreign materials.

Less common but just as detrimental will be a sudden change in a dog’s regular food, stress, allergies and just poor quality dog food in general. Food intolerance can also cause rapid transit. Many dogs seem unable to tolerate beef, pork, fish, eggs, spices, corn, wheat, soy, gravies, salts, spices, fats, and even some commercial dog foods.

There are also viruses, parasites and bacterial infections that can cause intermittent diarrhoea with the greatest problem being from roundworms, hookworms, whipworms, threadworms and giardia.  These causes can often be the hardest to spot as they will appear out of the blue and then disappear just as you are about to take the dog to the vet. Only to then re-appear a few weeks or even months later.

As you’d expect many pharmaceuticals can also cause diarrhea. It is quite common for heartworm tablets for example to cause bouts of diarrhoea. Non Steroidal anti inflammatories and antibiotics are also major culprits.

How to spot diarrhoea

Anyone who has experience of diarrhoea in an animal will know that it’s very hard to miss the signs! However it is worth looking out for some of the less obvious signs of impending diarrhoea. Although dogs will not understand what’s happening to them they will certainly feel the need to toilet and this can and will cause them a lot of distress, especially if they are in the home with no way to get out.

The first and most obvious sign is when your dog is standing anxiously at the door and needs to get out quickly. Other signs that can go along with diarrhea include fever, lethargy, malaise, loss of appetite, and dehydration.

A far less obvious sign is when your dog actually strains to go which can be misinterpreted as constipation. When an animal gets diarrhoea its natural rhythms of muscle contraction of the intestinal tract are upset and this can give them the feeling that they need to go even when they don’t as his colon may well be completely empty.

Although most cases of diarrhoea will eventually go reasonably quickly without intervention some higher risk groups such as puppies, smaller breeds and seniors can experience severe dehydration.

Have a good look!

This may not sound like the most enticing thing to do but have a good look, smell and even sometimes feel of your dog’s faeces. This can often tell you a lot about your dog’s condition.


Just the colour of your dog’s faeces can tell you a lot. Red or tarry faeces or red blood and clots may indicate GI bleeding. Pasty or light in colour may be due to a lack of bile and indicate a problem with the Liver. In these cases you should immediately take your dog to the vets. Large or rancid faeces may indicate inadequate digestion or absorption.


A watery consistency is likely to be due to rapid transit, foamy could be a bacterial infection and greasy could be due to malabsorption and pancreas issues


If it smells like food or sour milk it could be due to inadequate digestion and in puppies overfeeding whilst if the smell is rancid it could point to fermentation issues.


Several small stools in a day with straining could indicate colitis whilst three to five large stools in a day could indicate inadequate digestion or absorption issues

What should I do when my dog gets diarrhoea?

If your dog is generally healthy and behaving normally other than the diarrhoea then the first thing to do is stop all food for 24 hours. It is crucial that you do not stop water and this should be freely available.

Once the 24 hours has passed you should start feeding the dog a very bland diet that contains little or no fat.

White meat such as chicken breast would be great and even better if you have any turkey left over remove any grease and fat and grind it down and mix it with cooked sweet potato or instant mashed potato.

Mix this up in the ratio of 50:50 and feed 2-3 times per day for about three days or until the stools are back to normal.

You could also try ground beef but even the leanest beef will have reasonable amounts of fat in. Other easily digestible foods to try would be cottage cheese; cooked macaroni, cooked oatmeal, and soft-boiled eggs. Feed three or four small meals a day for the first two days. Then slowly switch the diet back to the dog’s regular food.

Bentonite Clay

If you looked at bentonite clay through a microscope, you’d see that it is made up of tiny platelets. These plates are of aluminosilicate that are separated by calcium ions. The separation of these plates by the positively charged calcium ions create a highly charged inner layer which can literally attract and trap materials. As the clay travels, it expands like a sponge as it absorbs water and toxins as it works its way through the body. It is effective in improving stool quality for most causes of acute and chronic diarrhoea. Bentonite Clay is sub classified as a ‘Smectite’ clay which has a three layered crystalline structure which exhibit the characteristic of hydrational swelling when exposed to water.

Once the clay has traveled through the digestive tract it is eliminated from the body, along with the toxins that are attached to it. I use this clay to clear up diarrhoea very successfully.

I’d recommend 1/8 teaspoon four times daily mixed with a small amount of food or mixed.

For long term maintenance and control of chronic diarrhoea, once the stools have responded to the initial I’d recommend 1/8 teaspoon for the next week.

Slippery Elm Bark

Slipper Elm preparations cause reflex stimulation of nerve endings in the GI tract, leading to mucous secretion which may protect the GI tract in cases of diarrhoea.

I’d recommend about a half teaspoon for each 5kg of body weight, mixed into the bland diet twice daily.


Feeding a bland diet containing bentonite clay and supplementing with slippery elm bark is a good plan for about 3 days, at which time your dog’s stool should be back to normal.

It’s important to make sure that your pet has access to clean drinking water at all times, and encourage your pet to drink if you can.


If this hasn’t worked after 72 hours or your dog is sluggish, running a fever or feels warm to the touch I would recommend you contact your vet.

If you see blood in your pet’s stool or he’s weak or shows any other signs of debilitation along with the diarrhoea, you should make an appointment with the vet.

If your dog seems fine but is experiencing recurrent bouts of diarrhoea, you should make an appointment.

It’s important to bring a sample of your dog’s stool to your vet appointment, even if it’s watery. This will help your vet identify potential underlying causes for the diarrhoea.

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