Vomiting and diarrhoea


What causes vomiting and diarrhoea?

The most common cause of vomiting and diarrhoea is gastroenteritis. Gastroenteritis is inflammation of the stomach and intestinal tract. Other signs of gastroenteritis may include lethargy, reduced appetite and abdominal pain. Gastroenteritis is most commonly induced by a change in diet. This may be intentional (for example, giving a treat or table scraps), or unintentional (the dog picking up something that it shouldn't). Fatty foods are the most common culprits. However, vomiting and diarrhoea can be caused by a wide variety of other conditions, including but not limited to:

  • Gastrointestinal infection (worms, viruses or bacteria)
  • Pancreatitis (see Information Sheet)
  • Toxicities (see Information Sheet)
  • Gastrointestinal foreign bodies
  • Renal disease (see Information Sheet)
  • Hepatic disease
  • Neoplasia (cancer)

How is gastroenteritis diagnosed?

The diagnosis of gastroenteritis is usually based on clinical signs, but it is important to also diagnose the underlying cause of gastroenteritis. If the condition is mild, and particularly if there is a history of dietary change, we may try symptomatic therapy first. If the condition is persistent or severe, we will normally recommend blood tests to check for evidence of infection, pancreatitis, renal or hepatic disease, or other more serious conditions.

What can I do to treat vomiting and diarrhoea at home?

If your pet is vomiting or has diarrhoea, you should start by worming him or her if he is not already up to date with worming. It is a good idea to use a 'spot-on' product, as it can't be vomited back up! If you need to use an oral treatment, the non-chewable products are less likely to induce vomiting. Next, fast him or her for at least 12–24 hours (withdraw food but leave free access to water). After this period of fasting, you should start feeding frequent small meals of a very bland food (rice and boiled chicken with no skin, fat or bones are ideal). Do not feed any treats, table scraps or regular dog food. Keep feeding small frequent bland meals for 48 hours after vomiting resolves, then gradually reintroduce your pet's normal diet. If you have identified what caused the upset, you should avoid feeding this in future. If your dog continues to vomit or becomes lethargic despite these measures, you need to seek veterinary help.

What other treatment is required?

If fasting and a bland diet do not resolve your pet's vomiting and diarrhoea, you should see a vet. We will examine your pet to check for any evidence of underlying problems and may recommend blood tests. The best way to treat vomiting and diarrhoea is to treat the underlying cause. However, there are some supportive treatments that we may recommend, including anti-nausea / anti-vomiting medications, gut protectant medications and pain relief medications. We may also prescribe antibiotics if we are concerned about infection. In some cases we may need to keep your pet in hospital for IV fluids and medications, particularly if he or she is dehydrated, not eating or unable to keep oral medications down.