A cat eating some grass

The surprising benefits of cat grass

What is cat grass?

Multiple species are often sold in mixed DIY grow-at-home kits. This barley is one of the more common ones..

Cat grass is an umbrella term for several different grass species that are grown and sold specifically to be chewed and swallowed by cats. These are the names of some of the most commonly used species, sorted by how often they are sold in pet stores:

  • Oatgrass (Arrhenatherum elatius)
  • Common Oat (Avena Sativa)
  • Barley (Hordeum vulgare)
  • Wheat (Thinopyrum intermedium)
  • Alfalfa grass (Medicago sativa)
  • Rye (Lolium perenne)
  • Umbrella papyrus (Cyperus Alternifolius or ‘zumula’)

So why do cats eat grass?

Cats are carnivores, which effectively means their entire body is built to digest meat. Plants, on the other hand, are easy to digest at all. In fact, eating greens will often cause them to gag or even vomit. So why do many cats still eat grass? As we’re about to find out, cat grass may actually hold some hidden benefits.

The theory of functional vomiting

One of the most recognized theories among experts is that the act of vomitting helps them remove clogged up hairs that got stuck in the intestinal tract. These are known as hairballs; the tiny balls of fur that cat owners may discover on the floor of their house every once in a while.

Expelling hairballs is very important to prevent painful blockages in the gut.
Vomitting may also help expel undigestable pieces of food left over in the stomach, like bits of teeth and calcified bone fragments.

Vitamins & trace minerals

Another often-heard theory is that cats nibble on grass to release chlorophyll and several other nutrients that are present inside the cells of grass leaves.


A collection of green pigments found in the leaves of plants, chlorophyll is what allows plants to extract energy from sunlight to do their photosynthesis and grow, Sunlight is the main source of energy on our planet. So without this bright green substance, there probably would be no life on earth!

Chefs often use chlorophyll to color a variety of foods green. Much like the fatty acids in salmon, ingesting chlorophyll is also associated with a whole range of health benefits. And while not all of these benefits have been scientifically proven, chlorophyll is a for sure a good supplement for a large number of things:

A cat chewing off green leaves from a plant
Green plant leaves contain lots of chlorophyll, a pigment used in photosynthesis. It also has multiple potential benefits when ingested.
  • stimulate the immune response
  • help combat skin diseases
  • reduce inflammation and bacterial growth
  • detoxification
  • prevent cancer

Folic Acid

This vitamin is essential for the production of hemoglobin (an important molecule that binds to oxygen and facillitates its’ transportation through the bloodstream in mammals).

Since folic acid is not present raw animal meat, it makes sense that wild cats needed to find a different source to get this essential vitamin in.

Nowadays, folic acid is commonly added to commercial cat food. This means that in most cases cat grass is not essential to a domestic cat for its’ folid acid content. But since many people are putting their cats on raw diets again, cat grass may still be useful as a supplement.


While grass works great as a laxative, it also contains a lot of healthy fiber. In case you’re wondering what fibers are, they are undigestible parts in food that help move food through the bowels and digest it efficiently. Like the act of vomitting, fiber may also help move clogged hairs through the intestines so that they can be pooped out.

So which is the best one?

All cat grasses are fine for consumption, but one particular species has special properties that could be beneficial for older cats: alfalfa grass. Scientific studies have shown that it can be useful in the treatment of renal diseases and even possibily help prevent them.

How much grass is my cat allowed to eat?

You may worry that your cat could get problems from eating too much grass, especially if it leads to frequent vomiting. But the truth is that larger quantities can be very helpful for the declogging and subsequent expelling of hairballs from the stomach. So how much cat grass is too much?

There is no limit to the amount of grass your cat is allowed to eat. Veterinarians generally agree that cat grass can be placed in a convenient spot and that your cat should be allowed to nibble away at her own discretion.

There is just one caveat: if your cat is vomiting every day, something is wrong and you should bring her to a vet immediately.

-> TIP: If you have multiple cats, consider giving each their own piece of grass. Why? Well, as we wrote inn our article on puzzle dispensers, cats don’t like it when they have to compete over their resources with other cats.

Is cat grass safe?

You can safely let your cat nibble away on a patch of grass. Just make sure there are no other harmful plants around.

The answer is yes, as long as you buy a species that is sold specifically for cats, your cat should not get problems from eating this grass. It may in fact be a safer alternative to your neighbours’ grass, which could be contaminated with pesticides. No substance found in catgrass is toxic to felines, and there are also no known cases of cats dieing from eating too much cat grass.

But other plants cán be dangerous..

One thing that should definitely not be overlooked is the fact that many other common household plants like aloe vera, ivies, lilies and carnations are highly dangerous when eaten by cats.

Your cat could easily mistake one for the other. If she needs additional fiber and the grass is almost gone, she could also try to nibble on another plant that is extremely poisonous too. We therefor highly encourage you not to place your cat grass right next to other household plants.

Is cat grass worth my money?

That depends how you look at it. Our perspective is that a patch of grass can easily be pulled from the soil for free,. If you do not want to go through the hassle of finding a good looking patch and taking it home, then a kit with some soil and seeds from the pet store may be a sold investment.

Cat grass is not very expensive in most stores anyway, going for roughly 3-7 euro or dollars per kit. You can’t really go wrong there!

Frequently asked questions

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  1. I’ve been telling my friends with indoor cats they should pick up some grass for ages, but most dont seem to make a priority of it. Personally i’ve always bought grass for my kitties Tommy and Blackie as I believe it is super helpful!

    There was quite a few interesting facts in this article that I never heard before. Thanks for the great read.

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