Gastroenteritis in dogs: causes, symptoms and treatments

It’s most commonly caused by infection or poor diet, but there are many possible causes. We outline some of the more common causes below.

What causes gastroenteritis in dogs?

Dietary causes

The most obvious dietary cause of gastroenteritis is eating food that’s gone off, but your dog is just as likely to contract the condition through overeating, a diet that’s too rich in fat, or eating a food type that they can’t tolerate.

Infection

Gastroenteritis in dogs can be caused by parasitic infections such as worms, viral infections such as infectious canine hepatitis and parvovirus, bacterial infections such as salmonella, and fungal infections.

Metabolic causes

Some conditions such as diabetes, liver disease and kidney disease can cause the acute vomiting and diarrhoea that are common signs of gastroenteritis in dogs.

Inflammatory bowel disease (IBD)

IBD is caused by a build-up of inflammatory cells in the gastrointestinal tract (GI), which can lead to vomiting and diarrhoea. The body reacting to something unusual (infection or food intolerance) often causes it.

Gastrointestinal blockages

Your dog’s gastrointestinal tract (GI) can become blocked due to a medical reason such as a tumour or growth, or by swallowing something they can’t digest – like an old sock or a toy.

Drugs and other toxic causes

The sickness and diarrhoea that are common signs of gastroenteritis in dogs can sometimes be a reaction to a toxic chemical. Certain substances such as antifreeze, insecticides and pesticides are highly toxic to dogs. Swallowing them can cause sudden vomiting and diarrhoea, so it’s vital to keep these safely out of your dog’s reach.

Abdominal disorders

Sickness and diarrhoea in dogs can also be a side-effect of abdominal conditions such as pancreatitis (inflammation of the pancreas), peritonitis (inflammation of the abdominal lining), and prostatitis (inflammation of the prostate).

“Gastroentiritis is a nasty condition that causes inflammation of the stomach and intestinal lining, often recognised by sudden vomiting and diarrhoea.”

Signs and symptoms

As well as sudden sickness and diarrhoea – both of which commonly contain blood – other symptoms of gastroenteritis in dogs include:

• Fever
• Loss of appetite
• Dehydration 
• Depression
• Nausea
• Abdominal pain
• Red or black stools (both are signs of bleeding in the bowel). 

How is gastroenteritis treated?

Your vet will recommend the most appropriate and effective treatment for your dog depending on the cause of the gastroenteritis. This may include medication or a specific anti-parasitic treatment, sometimes it may be suggested that your dog is starved of food for a short period.

Whatever the cause, it’s vital to give your dog plenty of water while they recover, as sickness and diarrhoea can cause serious dehydration. 

Need more advice?

If your dog shows sudden signs of sickness and diarrhoea, get in touch with your local vet immediately.

Find your nearest vet using our Find a Vet page, or speak to a vet online using Online Vets.