Why does my cat eat grass?

You may have noticed your cat eating grass. Don’t worry, they haven’t gone vegetarian! It’s perfectly normal - and there are a few theories as to why they are eating some greens!

Cats are known as ‘obligate carnivores’, which means their nutritional needs are met by eating only meat - so why do they eat grass?

One theory is that cats consume grass to help with their digestive system. Grass is a source of fibre, and it may be that your cat needs some additional fibre to keep their digestive system moving along nicely, just as humans do. Some cats appear to eat grass and throw it up soon after, which may be their way of ‘getting rid’ of any harmful food, fur or bones, they have ingested.

A report published in 2019 by the International Society for Applied Ethology in Bergen, Norway, suggests another reason. Eating grass helps your cat expel nasty internal parasites, making the digestive tract muscles work harder to move along the parasites. Due to preventive treatments, most cats in the UK today don’t have the same parasites in their bodies as they used to, however, the scientists involved in this study think the habit evolved many years ago, in the ancestors of today’s cat.

While it doesn’t harm your cat to eat grass, it is worth remembering that some gardeners use pesticides and fertilisers on their lawns and plants. These chemicals are not designed to be ingested by cats and could be harmful. So, if you know your cat enjoys eating grass, switch to more natural gardening methods.

Eating grass can cause other issues in cats, as Robin Hargreaves, Senior Veterinary Advisor at Agria Pet Insurance, explains:
"One interesting phenomenon we regularly see in summer is cats with grass lodged in the back of the nose, causing acute gagging and discomfort when eating or loss of appetite. They often go outside and come back a little later, suddenly swallowing/gagging/retching with various degrees of severity.

"Usually, these cats have brought most of the consumed grass back up, but a stiff blade has gone up the back of the nose over the soft palate rather than into the mouth. Because cats often eat the stiff and serrated blades of grass, it won't come back down, but rather ratchets itself further and further up, even sometimes emerging from the nose. This is so common that we can have a cat or two a week in summer requiring a general anaesthetic to remove a blade from the nasopharynx."

Cat grass, also known as pet grass, can help cats enjoy grass without them eating the harmful varieties. This is indoor grass for cats that you can easily grow on a windowsill or outside in the warmer months. Cat grass is excellent for indoor cats, too, so they can eat grass if their instinct tells them to, even if they haven’t got access to the great outdoors.

It is worth noting if your cat seems to be eating excessive amounts of grass, they may have a problem with their digestive system. If you suspect this is the case, get your cat checked out by your vet.

If you have an Agria Pet Insurance policy, you can access the free Pet Health Helpline, 24 hours a day, 7 days a week. The veterinary-trained team will advise on any concerns or queries that you may have over your pet’s health – much like the NHS 111 service for people. Call free on 03333 32 19 47.