What your dog’s poo tells you about their health?

11th December 2021

Poo… it is something you get used to dealing with if you’re a dog owner! But did you know that our dog’s poo can tell us an awful lot about their health? Read on to find out whether your dog’s poo is normal and the steps you should take if things aren’t quite right…

What Does Normal Dog Poo Look Like?

Most healthy dogs should be producing stools once or twice a day depending on their diet and exercise regime. This stool should be a uniform chocolate brown colour with no blood or noticeable mucus. It should also be well-formed with some segmentation, and have a firm (but not hard) consistency. When you pick the poo up it should not leave much residue behind. 

Some vets will refer to a faecal scoring chart when discussing your dog’s stools. This allows the vet to grade the consistency of your dog’s poo from 1 to 7, with 1 being a very firm, hard and constipated type of poo and 7 being watery, diarrhoea. A grade 2 is the ideal poo, that we described previously, and should be what you are aiming for with your dog.

What if your Dog’s Poo is Hard and Dry?

If your dog has very hard poo which he is struggling to pass, then he may well be constipated. This poo is usually small and often forms hard balls or nuggets. Dogs that are constipated will pass stools much less frequently than normal too, and could have other symptoms such as loss of appetite or vomiting. Constipation can be caused by reduced moisture and fibre content in the diet, or by a physical obstruction. Some of the reasons why your dog may be constipated include –


This can be caused by not drinking enough or through illness, which can make your dog’s stools harder than normal and more difficult to pass.

Inappropriate diet  

A diet that is lacking in fibre may cause your dog to become constipated, or eating a diet that contains a high proportion of bones can cause some dogs to struggle with passing stools

Lack of exercise 

Exercise helps to keep the digestive system in good working order and so inactivity can lead to constipation

Eating things he shouldn’t do (pica) 

Foreign material like stones or bedding material in your dog’s digestive tract could make stools tricky to pass.

An obstruction near the anus 

A tumour, growth or a stricture (narrowing) in your dog’s back passage could make it tricky for your pet to pass stools.


Some animals with painful conditions may find it tricky to get into the right position to pass faeces and could become constipated.

You should always consult your vet if your dog is constipated, but you can help your dog generally by providing plenty of fresh water, feeding a diet that is well balanced and discouraging him from eating non-digestible items.

Loose stools and Watery Diarrhoea in Dogs

Diarrhoea is usually used to describe poo which is very loose and watery. It’s a common problem in veterinary practice, making up around 3% of dog consultations. Your dog may be going to the toilet more frequently than normal and have other accompanying symptoms such as vomiting, lethargy and abdominal discomfort. 

Your dog may be going to the toilet more frequently than normal and have other accompanying symptoms such as vomiting, lethargy and abdominal discomfort. This is commonly caused what we call “dietary indiscretion.” In other words, your dog has been eating something it shouldn’t, like compost or discarded waste food. In other cases it could be caused by sensitivities to certain foods or allergies.

However, loose stools in dogs is a very non-specific sign and in some cases could be caused by an array of different conditions including:

  • Parasite infections
  • Bacterial and viral infections
  • Endocrine conditions such as Addison’s Disease
  • Pancreatitis
  • Inflammatory bowel disease
  • Various cancers
  • Side effects of some medication

If your dog is experiencing prolonged loose stools, do go and see your vet.

Blood in dog poo

Fresh blood in faeces can be seen as red streaks or droplets. This usually indicates that there is inflammation going on in the lower digestive tract or rectum (back passage). There could be several causes for this inflammation, so it’s best to get your pet checked out if you have seen blood in their poo.

Mucus in dog poo

A small amount of mucus from time to time is normal, as this is what helps lubricate the poo as it passes through the digestive tract. But large amounts of mucus could appear as a slimy jelly-like coating over the surface of the stool, sometimes even looking like a casing or skin over it. This is usually caused by inflammation in the colon (‘colitis’) of which there are many underlying triggers. Mucus can sometimes be accompanied by other symptoms too such as soft, loose stools or blood.

What Colour Should my Dog’s Poo Be?

Healthy dog poo should be a chocolatey brown colour, but varies depending on their diet. You’ll quickly learn what’s normal for your dog, but if there are any changes to the colour of your dog’s poo, you should investigate. Dog poo colour change could indicate possible health concerns as highlighted below.

White dog poo

White dog poo can sometimes be seen where there are high levels of calcium in the diet, for example when dogs eat a lot of bones. Small white flecks in the poo however could indicate tapeworm.

Black dog poo

If you see a stool that is black with a sticky tar-like appearance, then it could indicate digested blood in the faeces. This is called melaena and is a serious sign that there is something untoward going on. A bleed in the upper digestive tract from a stomach ulcer, coagulation disorder or tumour could cause melaena. Make sure you take your dog to the vet urgently for an examination.

Orange/yellow dog poo

Stools this colour could indicate that food has passed too quickly along the digestive tract and hasn’t been processed properly. Underlying liver issues could contribute to this.

Smelly dog poo

Dog poo doesn’t smell amazing at the best of times, but if you are noticing a fouler odour than normal or your dog also has accompanying smelly wind, it could be a sign that their digestive tract is struggling. Sometimes other symptoms are seen like loose stools or vomiting. If your dog’s poo is otherwise normal, you could try him on a different brand of food to see if this helps.


Poo can tell us a lot about our dog’s health status. If they aren’t producing the optimum stool or if there is a change in how frequently they are passing faeces, then you should consider seeking advice. 

Ensuring your pet is on a good quality complete diet, has access to plenty of fresh water and are having routine preventative treatments like worming and vaccinations, will all help prevent problems. If you have any concerns that your dog is unwell, call your vet for advice as many conditions do better with early intervention.

By Dr Rebecca MacMillan BVetMed MRCVS