Why Do Cats Eat Grass?

One of the great mysteries of cat ownership is why cats seem to enjoy eating grass so much, especially as it appears to make them sick. If you’re one of the many cat owners wondering ‘why does my cat keep being sick?’ then you’re probably also familiar with the telltale blades of grass in the mess you have to clean up.

Today we’re taking a look at this phenomenon, to find the answers that will make you a better, more informed cat owner.

Does Grass Make Cats Sick?

The most widespread explanation for why cats eat grass is that it makes them throw up, and when cats have eaten something that disagrees with them (and as prolific hunters and scavengers, this is far from a rare occurrence) they nibble on grass to help purge their system.

Grass does cause cats to throw up because they don’t have the enzymes in their stomach to digest the tough plant matter. Unfortunately though, there’s no evidence that cats eat grass on purpose to settle an upset stomach. When cats have eaten spoiled food, they don’t need any further assistance to throw it up, and eating grass when they feel sick would require a more complex understanding of cause and effect than we believe cats have.

Intestinal Health

Scientists have come up with another reason why your cat may have that instinctive to add some grass to their diet. As well as causing vomiting, it also stimulates muscles in the intestinal tract helping them to expel parasites! 

While they might not know why they’re doing it, this urge is helping them maintain a healthy gut! Unfortunately, it doesn’t actually help with this aim! The parasites that lead to your cat inheriting this urge don’t infect modern cats – this is a behaviour adopted by ancestral, feral cats and passed on.

Folic Acid

Another possible explanation is that grass contains folic acid, which cats use in their digestive system. Even though they can’t break down grass fully in their stomach, it does give them a folic acid boost, a little like us taking a vitamin supplement!

Cats can’t tell they need a dose of this compound and make a decision to eat grass to top up – not in the same way we decide it’s time to pick up a pack of multivitamins from the chemist. All they know is sometimes grass will smell more delicious to them, and then it’s time for a folic acid snack!