Chronic Vomiting & Diarrhoea

Diagnosing and Managing Chronic Vomiting and/or Diarrhoea

Your pet may have come to see us with chronic (longer than 2 weeks) or recurrent symptoms of a digestive upset. The symptoms can be very varied and include:

  • Vomiting.
  • Regurgitation.
  • Reflux.
  • Burping.
  • Inappetence.
  • A gurgly tummy.
  • Diarrhoea.
  • Mucoid covering on the stools.                  
  • Blood in stools.
  • Farting.

What can cause this?

Problems in the gut can include:

  • Infections such as viruses, Campylobacter, Giardia, and Tritrichomonas (cats) (care as these can sometimes infect people).
  • Adverse food reactions.
  • Inflammatory Bowel Disease.
  • Foreign Body.
  • Cancer.

Sometimes problems outside of the gut can cause digestive problems:


  • Pancreatitis.
  • Cancer.
  • Pancreatic insufficiency – not making digestive enzymes.


  • Hepatitis.
  • Cancer.
  • Gall bladder inflammation or infection.

Other problems include:

  • Kidney failure.
  • Brachycephalic Obstructive Airway Syndrome and other diseases in the chest can cause chronic reflux.
  • Prostate infections and cancer can cause inappetence and straining to pass faeces.
  • Infections of the womb can cause vomiting and diarrhoea.
  • Neurological (brain) diseases can sometimes cause vomiting.
  • Addisons is a hormonal problem usually seen in young dogs, it can cause recurrent vomiting and diarrhoea.

How do we investigate this?

The exact order of testing will depend on the age of your pet, their breed, and their symptoms. In most pets the order of testing will often look like:

  1. If mainly diarrhoea, faecal samples to rule out Giardia and other infections.
  2. If mainly vomiting, x-rays to rule out a foreign body.
  3. Shop bought food/home cooked trial.
  4. Blood tests to rule out Addisons and assess organ function.
  5. Abdominal ultrasound.
  6. Prescription food trial.
  7. Steroid trial.
  8. Panacur trial (a type of wormer).
  9. Gut biopsies.
  10. Antibiotic trial.

Why don’t we give antibiotics sooner?

Antibiotics are an important resource for humans and we must protect them so they work for us in the future. The use of antibiotics in gut infections often promotes the development of resistance, making these drugs ineffective for future use.

In most cases antibiotics will only temporarily help your pet as they are not dealing with the underlying cause of the diarrhoea. Antibiotics can also cause something called dysbiosis, whereby the balance of good and bad bacteria in the gut is adversely affected for a long time after the antibiotics.

It can take a while to make a firm diagnosis and management plan for each case. If your pet needs a food trial, we will provide you with information on how to do this. Please do not start a food trial without discussing it with us first.

If you have any further questions regarding your pets care please do not hesitate to ask us, either in your next appointment, or via email

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