Diarrhoea in dogs is a symptom of an underlying problem and not a disease in itself, it should always be cause for concern. Diarrhoea dehydrates the body and can have a devastating effect. If it is accompanied by vomiting, lethargy or any other behavioural changes it should be treated as a medical emergency.

A bout of diarrhoea can be caused by a change in food type, an unfamiliar treat or feeding table scraps. As long as your dog is acting normally, diarrhoea caused by food changes can often be resolved by withholding food (not water) for 24 hours allowing the digestive system to settle down. After 24 hours, small amounts of bland food can slowly be re-introduced. To avoid diarrhoea, change your dog’s diet gradually over several days. Large amounts of meat or fatty foods from human plates can be far too rich for a dog’s digestion and cause diarrhoea and vomiting and can also cause pancreatitis.

Intestinal parasites are common causes of diarrhoea. Puppies are especially susceptible to roundworms. Roundworms can grow to up to 15cm long and appear spaghetti-like. Signs of a worm infestation are a pot-bellied appearance, poor growth, a rough, dull hair coat, diarrhoea and vomiting.

The single-celled internal parasite Giardia lives in the intestines of infected animals. Its most common symptom is diarrhoea of varying severity. Transmitted from pet to pet, through contaminated feed or water and through the soil, Giardia can show no symptoms for extended periods of time making routine testing important. Coccidia is another single-celled organism that infects the small intestine. Dogs with coccidia may show no signs of illness but some may have severe bouts of watery stools, bloody diarrhoea, vomiting, depression and fever.

Diarrhoea in puppies is of particular concern because it is often the first symptom of severe and potentially fatal viral diseases such as the parvovirus, coronavirus or distemper. Parvovirus is most commonly found in unvaccinated puppies. The symptoms are a high fever, lethargy, loss of appetite and liquid diarrhoea. Coronavirus is also a highly contagious virus. Adult dogs may simply show symptoms such as stomach flu and recover within a few days but puppies can develop far more serious infections and complications. The signs of coronavirus are extreme watery diarrhoea. The Canine Distemper Virus is highly contagious causing a high fever, coughing and sneezing followed by vomiting and dark, tar-coloured diarrhoea. Finally the virus causes seizures and can often be fatal. Vaccination is the best way to prevent viral diseases.

Other causes of acute diarrhoea in dogs can include bacterial infections, such as salmonella and E-coli, toxin exposure and even stress.

Treatment of acute diarrhoea in dogs is aimed at diagnosing and correcting the underlying problem. If your dog has had loose stools for less than 24 hours but is otherwise acting normally (normal energy level, eating and drinking normally), you may just be able to wait and see how he does. However, be in the look out if your dog is showing any additional signs of distress or has had increasing amounts of diarrhoea for any length of time.

Diarrhoea that persists for three or more weeks is considered chronic and can lead to poor digestion and absorption of nutrients. Dogs will often not eat properly, have low energy levels and poor quality coat. Food allergies and intolerances cause chronic inflammation in the intestinal tract and are a common cause of mild chronic diarrhoea. Pancreatitis causes diarrhoea, abdominal pain, vomiting and a poor appetite. Because these symptoms are shared with so many other gastrointestinal problems, pancreatitis can be hard to diagnose. Inflammatory bowel disease (IBD) can also be a cause of chronic diarrhoea in dogs. Dogs with a long history of diarrhoea or weight loss who are free of parasites and diarrhoea causing agents should be considered for IBD.

Diarrhoea is almost always a sign of an underlying medical condition that needs to be addressed and the presence of diarrhoea in any puppy should be treated as a medical emergency until proven otherwise.

Disclaimer: The above article is not intended as a substitute for the advice of a veterinarian nor is the source to be used as a diagnostic tool as there may be various conditions that may resemble the descriptions provided.