What is Diarrhoea in Dogs?

Diarrhoea is more frequent, loose watery stools. Usually seen as a symptom of an intestinal upset. Colour change may also be seen and/or a presence of mucus and blood.

Diarrhoea can occur in dogs for a variety of reasons affecting any age and can generally be categorised into two forms:

1. Acute Diarrhoea- sudden onset lasting a few weeks.
2. Chronic Diarrhoea – longer than a few weeks.

Our guide contains expert advice from qualified and registered veterinary nurses to help you choose the best course of action for your pet and help answer your question – why does my dog have diarrhoea?

Symptoms and signs of diarrhoea in cats
• Loose or watery stools
• Increase in frequency toileting
• Weight loss
• Vomiting
• Pale gums
• Weakness
• Anorexia
• Fever
• Dehydration
• Mucus/blood in stools
• Lethargic/Depressed
• Straining to defecate/pass faeces
• Increased drinking

Why has my Dog got diarrhoea?

Diarrhoea can often present as a result of a number of underlying causes in dog. Your dog may be a scavenger or a dietary change. Certain health conditions such liver disease, bacterial and viral infections.
Frequent watery stools often with a strong smell or colour change may be seen. In a lot of cases diarrhoea will resolve on its own.

At PetGP our Registered Veterinary Nurses are on hand to offer advice call us at PetGP to help assess.

Telephone the PetGP nurse on 0333 332 7883

Diarrhoea in dogs can be caused by several underlying reasons.

• Diet Change – This could be a sudden change in your dog’s food or introduction of a new food. Diarrhoea can also be a result of an intolerance or allergy.
• Medication – a common side effect that can be seen in dogs on medication is diarrhoea contacting your vet in this situation is advisable.
• Parasites – worms such roundworm, hookworms, gardia, coccidia can cause diarrhoea in dogs.
• Bacterial – Including Salmonella and E.Coli cause side effects including diarrhoea.
• Viral Infections – Parvovirus, Distemper, Coronvirus are viral infections in dogs which may cause diarrhoea.
• Systemic Illness – Liver and Kidney disease, Pancreatitis, Diabetes Mellitus may show signs of diarrhoea in dogs.
• Toxins – Chocolate, onions, raisins if ingested can cause diarrhoea in dogs.
• Tumours – diarrhoea can be seen.

Triage of Diarrhoea in Dogs

Q. Has your dog eaten anything out of the ordinary?
Rule out any possible toxins or poisons your dog may have been in contact with or ingested. Are there any lilies in the house, or has your cat eaten anything unusual? Diarrhoea can be the result of a number of factors but if there is a suspected risk of poison or exposure contact your vet asap.

Q. Is there any blood in the diarrhoea this could be bright red or black?
In dogs with Diarrhoea any blood can be a result of straining while passing soft of water diarrhoea. Small traces or flecks may be seen but more than this or any black or dark blood can be a sign of more serious issues.

Q. Has your dog been vomiting?
If your dog is also vomiting the risk of dehydration increases our nurses can help run through some checks to help triage and see how your dog is doing.

Q. Is your dog on any medication?
Some medications may cause side effects, if your dog is on medication any changes to your pet such as diarrhoea should be highlighted to your vet.

Q. How long has your dog had diarrhoea?
A sudden onset of diarrhoea in a healthy dog may happen due to a number of factors such as diet change, scavenging, intolerance contact us to have a chat.

Call us At PetGP our Registered Veterinary Nurses are on hand to offer advice call us at PetGP to help assess.

Telephone the PetGP nurse on 0333 332 7883

Diagnosis of Diarrhoea in Dogs by your vet


Your vet will give your dog a thorough examination and take a full history from you, including any symptoms or changes seen. The vet will determine the best action to take when carrying out a physical examination will check for any such signs including discomfort, dehydration and high temperature. Your vet may want to perform a few tests, including blood tests. A blood sample and urinalysis may be necessary to help highlight any causes of illness. Other tests can be useful, such as faecal samples to confirm parasitic infections or a biopsy from your dog’s intestines for histology. Radiographic x-rays may also be necessary and assist in diagnosing obstructions such as a foreign body.
It will be important for a veterinary professional to know the age of your pet as there are specific complaints that affect puppies and older dogs.

Treatment of Diarrhoea in Dogs

Diarrhoea lasting less than 24 hours in a healthy well dog may be monitored initially and by following certain advice. BUT

Contact Your Vet if:
• Blood/Tar like colour evident
• Lethargic, dull, depressed
• Puppy is less than a year old
• Fever
• Signs of pain – unusual posture, vocalisation, hunched.

At PetGP our Registered Veterinary Nurses are on hand to offer advice call us at PetGP to help assess.

How it Works

Telephone the PetGP nurse on 0333 332 7883

Home management of Diarrhoea in Dogs.

Step One – Dietary Rest: Most puppies/dogs with diarrhoea do not require a period of complete dietary rest. In fact feeding your puppy a bland diet will aid their intestinal recovery. The only time a period of rest from food would be advisable would be if your dog was also vomiting. In this instance a period of rest of 6 hours may be advisable to allow the stomach/intestines to recover. Dogs with diarrhoea have an inflamed bowel and have difficulty absorbing nutrients from their food. They often may not feel like eating. Puppies do not have the bodily reserves of an older dog and when food intake is reduced for a period of time they can very quickly become hypogylcaemic (develop low blood sugar). This can be a life threatening condition and the younger or smaller the puppy, the more likely this is to happen and the quicker it can come on. Signs can include listlessness, depression, staggering gait, muscular weakness, and tremors – especially of the face.

If you have concerns that this may have occurred contact your vet ASAP for advice. Feeding a puppy/dog their normal diet may be too rich for the inflamed tummy to cope with and may lead to prolonged diarrhoea. This would lead to further fluid loss and an increased risk of dehydration and hypoglycaemia. It is preferable to feed an easily digested and bland diet. Whilst your puppy/dog has diarrhoea you should always make fresh water available – you must not withhold water from your puppy. Withholding water could rapidly lead to dehydration and should be avoided. In the case of the puppy that is vomiting as well, you will need to monitor and control what they drink to prevent the puppy drinking large volumes of water that may lead to prolonged vomiting.

In general, a thirsty puppy will drink, so if your puppy remains fairly bright there should be no need to force them to drink, just ensure they can access fresh water at all times. Perhaps encourage drinking by encouraging the puppy to lick water from your fingers or an ice cube.
Puppies with self-limiting diarrhoea may vomit in the early stages but, as they improve, the vomiting should ease. If repeated vomiting or regurgitation of water occurs, contact a vet for advice ASAP

Step Two – High Digestibility Diet Whilst a puppy/dog is suffering from diarrhoea, it is best if normal foods are temporarily replaced with a restricted diet fed in small frequent meals, say 4-6 times daily. Food should be given in small quantities. Remember that a small puppy/dog may only have a stomach the size of a walnut. Many puppy diets are very high in meat protein (especially the premium brand tinned puppy foods) and can be difficult for a puppy with tummy problems to digest. Therefore it is best if the puppy’s normal food is temporarily replaced with a home-cooked bland diet.

Examples of a bland diet are: Boiled chicken and rice/pasta. White fish and rice/pasta or scrambled eggs with rice/pasta. After 2 to 3 days, as long as the diarrhoea is starting to clear up, the puppy’s normal food can be carefully re-introduced, by gradually weaning the puppy back over a period of 3 to 5 days.

Vet Nurse Topical Tips

• Be firm with your puppy/dog and give no titbits during the recovery period as they can cause a relapse.
• Walk your dog/puppy on a lead during the recovery period to prevent it scavenging on walks. The same applies when in the garden.
• Take your time when reintroducing your dog back to its usual diet. Rushing this stage is a common cause of the diarrhoea starting again. Imagine yourself in the same situation having eaten chicken soup for 2 days and then tucking into curry, your tummy may object too!
• Don’t expect your dog’s poo to look normal straight away, it may take several days. However you should see a gradual improvement every day. NOTE: Veterinary advice must be sought if your puppy’s condition deteriorates or does not improve.
Treatment of Dogs with Diarrhoea
• Dietary – avoid any sudden changes and treats to your dog’s diet, where allergies are suspected your vets can suggest options such as a hypoallergenic diet or options to help support your dog.
• Parasites (Intestinal) – worming/anti-parasitic treatment may be needed to remove the cause and supportive care if your dog.
• Bacterial/Viral Infections – Diagnosing to confirm the infection by your Vet along with supportive care, intravenous fluids and antibiotics.
• Obstruction (Intestinal) – this may be in the form of a foreign body or damage to the intestines from trauma your vet will assist with surgery/treatment to remove or pass the blockage.
• Toxins/Poisons – Onions, chocolate, raisins for example a quick diagnosis is often needed and supportive care, inducing vomiting where appropriate
• Cancer – surgery, chemotherapy
• IBS (Irritable Bowel Syndrome) – supportive, highly digestible diet.
• IBD (Idiopathic Inflammatory Bowel Disease) – highly digestible diet, medication to support the IBD.

Prevention of Diarrhoea in Dogs

To help avoid the risk of diarrhoea or soft stools in dogs, try to make any diet changes gradually. Mix the new food in with your dog’s old food to help reduce the risk of gastrointestinal upset. Avoid keeping anything toxic such as chocolate around your dog when unsupervised.

Frequently asked questions about diarrhoea in Dogs

My dogs got soft stools, runny poo?
If this is a sudden onset of diarrhoea and your dog is eating, drinking and well. It may be an option to try introducing a bland diet and following the home care advice.

What causes dogs to have diarrhoea?
Diarrhoea in dogs can result from a number of causes such as diet change, scavenging an underlying health issues.

What to feed dogs with diarrhoea?
A bland diet of chicken and pasta or white fish and rice should be fed.

My puppy has ongoing diarrhoea?
A puppy with diarrhoea maybe at risk of dehydration contact your vet.

call us at PetGP to help assess.

Telephone the PetGP nurse on 0333 332 7883

BSAVA Textbook of Veterinary Nursing (BSAVA British Small Animal Veterinary Association) Paperback – 28 Oct 2011
Handbook of Veterinary Nursing Paperback – 1 Oct 2010