Why does my cat eat grass?

Q As soon as we let one of our cats out he's straight on the lawn and will happily stay out there constantly eating grass for half an hour or so. We sometimes buy him indoor grass but we have to take it away from him to save him eating the whole container in one sitting. He likes anything grass like including my indoor plants. He is never normally sick from eating the grass. Very occasionally he is sick and brings up a lot of grass but this has been just a handful of times since we have had them. Is this normal?

Joe Inglis writes: Grass eating is something that is more common in dogs than cats so it is unusual to hear about a cat being so keen on grazing the lawn. There are many theories suggested for why pets at grass, ranging from deficiencies in their diets to behavioural problems, but there is no strong evidence to back up any of them – which leaves me to conclude that in this case like others, the cause is simply that he likes eating grass! If this is the case it is highly unlikely that this habit will cause any health problems, except for an occasional bought of sickness or diarrhoea, so there is no need to be unduly worried or try to curb his grazing unless he is obviously suffering from regular digestive upsets – and it may also save you from regular mowing!