Diarrhea in cat

If you notice that your cat is going to the litter tray more often than usual, and his orher stool is more liquid, or has an increased volume compared to normal, then she may have diarrhoea. Diarrhoea is defined as an increase in the frequency, volume, or liquid content of faeces, leading to unformed stools.Consistency of diarrhoea can vary from soft but formed through to liquid/watery and the colour can be darker or lighter than normal stools or even green, red or yellow.

Do not worry, most of the time diarrhoea is temporary and not serious and in most cases, the problem can be solved quickly with a simple change of diet, or appropriate medical treatment from your veterinary surgeon. The severity and the duration of diarrhoea episodes varies depending on the underlying cause. Diarrhoea is usually classified as either:

  • - acute (sudden onset and short lived) or chronic (more than 2-3 weeks duration)
  • - persistent (constant) or intermittent (i.e. comes and goes)


Diarrhoea in cats can occur for a wide variety of different reasons, and in chronic cases it is vital for your veterinary surgeon to find out the exact cause in order to determine the optimal treatment for your particular cat. Causes include:

  • - Abrupt change of diet or introduction of a new food withouta gradual transition
  • - Food allergy or intolerance to a certain food ingredient
  • - Infectious agents (viruses, parasites or bacteria )
  • - Inflammatory bowel disease – an inflammation of the intestines associated with chronic diarrhoea
  • - Tumours of the bowel or other organs
  • - Disease affecting other parts of the body (e.g. thyroid, liver or pancreas) which in turn affect the intestinal tract

What you can do

Often episodes of diarrhoea are not severe, have a short duration lasting only for few days and stop spontaneously. When diarrhoea lasts for more than a couple of days you should:

Always provide your cat with fresh clean water

  1. 1) “Rest” the gut by withholding food (but not water) for 24 hours then slowly reintroducing a highly digestible diet in small meals. A cat should not be deprived of food for more than 24 hours though as this can be detrimental
  2. 2) Contact your veterinary surgeon for a clinical investigation to identify the cause and determinethe most appropriatetherapy and diet. To help your veterinary surgeonin theirinvestigation, you should note and share the following information with your vet:
    • - Severity and frequency of the diarrhoea episodes
    • - Duration of diarrhoea
    • - Presence or absence of weight loss
    • - Change in appetite
    • - Presence of blood or mucus in the stools
    • - Colour of the stools
    • - Consistency of the stools (always loose or loose to formed)
    • - Volume of the stools (always increased or normal /increased)
    • - Presence or absence of straining when stools are passed
    • - Any additional clinical signs (e.g. vomiting, hyperactivity)
    • - Frequency and type of worming treatment given to your cat

Your veterinary surgeon will advise if any tests are required to determine the cause of the diarrhoea. Stool, blood and urine samples are often collected initially, and ultrasound, X- Rays, endoscopy and biopsies may be required if the condition is more chronic.

Once the diarrhoea episode has resolved, it will be very useful to keep an eye on the stool quality in the litter tray. This will allow you to detect early any change in quality, frequency or volume in the future.

Optimal diet for cats or kittens with diarrhoea

If your cat has mild diarrhoea or enteritis she will benefit from a diet with the following attributes:

  • - High quality, highly digestible ingredients: to reduce gut workload and help improve food tolerance
  • - Restricted number of protein sources to reduce the risk of an allergic reaction or adverse gastrointestinal reaction
  • - Prebiotics to help improve microbial balance and stimulate the growth of beneficial bacteria in the gut

If your veterinary surgeon suspects a food allergy is the cause of your cat’s diarrhoea then they may recommend a hypoallergenic diet formulated with hydrolysed proteins. These are proteins which are broken down into very small pieces which are unable or highly unlikely to cause an allergic reaction.

Talk to your vet about which diet they recommend is best for your cat.

How to improve your cat's digestion

Cat diarrhoea: what you can do