Why Do Cats Eat Grass?

By Sviat Oleksiv | Updated on September 6, 2021

Why Do Cats Eat Grass?

Have you ever wondered, why cats eat grass? Here is the answer!

Have you ever wondered why your cat sometimes nibbles on grass? The first time I saw my cat eating grass I thought it seemed strange and it is a question that vets are asked regularly but it turns out there’s actually a very good reason for the behaviour.

Why do cats eat grass? Ingesting grass is ultimately a way for your cat to relieve an upset stomach. By consuming grass, they can induce vomiting allowing them to bring up hairballs and other nondigestible materials that are present within their digestive system. As well as this, there are important nutrients in grass such as folic acid and the fiber of grass can help to aid in digestion and encourage regular bowel movements.

Although there are multiple benefits to your cat eating grass, not all grass is safe for them to ingest. After reading about the benefits, you may decide to start offering non-toxic grass to your cat – this is great for adults but it is best not to offer grass to kittens as it can be too harsh on their still developing digestive systems.

Key Reasons Cats Eat Grass

Although it may seem surprising, eating grass is an instinctive behaviour that can be witnessed in all cats, even cats in the wild can be seen occasionally chewing on grass. A wild cat may not regularly eat grass directly but they will be consuming it as part of their diet in another way; through their prey. When a cat eats their prey, they will also be consuming the contents of their prey’s stomach and this includes grass and plant material. Although this is a hidden factor that is not often considered, it is a way that a cat’s diet also includes grass.

There are a few key reasons a cat may eat grass including; when they are craving a specific nutrient, when they are blocked up and need assistance in digesting food and when they want to encourage vomiting so they can expel items that they are not able to digest. It’s all about their digestive system and helping it to work in the best way. Some people liken cats eating grass to a human taking an antacid, it just helps to relieve stomach upsets and gets everything working as it should.

With this in mind, your cat may seem perfectly healthy and happy but it is likely that they are nibbling on grass to help relieve an upset stomach. Don’t worry though as it is perfectly natural and they should be able to sort themselves out without you intervening. Although, there are certain situations where seeing your cat eating grass can cause concern, particularly if they are eating it excessively or are showing signs of poisoning.

Nutritional Benefits of Grass

Although cats are obligate carnivores which means they are strict meat eaters, they do occasionally ingest grass for the nutrients it contains. Grass has trace amounts of Vitamin A, Vitamin D and niacin as well as chlorophyll which helps to oxygenate the blood. It also contains folic acid which is a protein that is essential for a cat’s bodily functions and pays an important role in haemoglobin production. Without enough folic acid, a cat will become nutritionally deficient which can lead to anaemia and growth development issues.

Grass Aids Digestion

Eating grass adds fiber and can assist in encouraging regular bowel movements. A cat’s digestive tract can get blocked up with fur and other indigestible material and consuming grass appears to have a natural laxative effect in the sense that it gets the digestive system working and moving again. The lack of whole prey that indoor cats consume means they will likely not require much grass in their diet as they shouldn’t have indigestible materials such as feathers and bones in their digestive system, however they will still have hairballs which is the likely reason they still occasionally eat grass.

How Eating Grass Helps Control Hairballs

One of the big things that concerns cat owners (it concerned me at first too) is seeing your cat vomit after eating grass. This is actually something your cat is doing on purpose as they cannot digest a large amount of grass so they intentionally consume it to then throw it back up. Throwing up the grass also allows your cat to throw up any fur, feathers, bones or parasites that are in their digestive tract. After throwing up and clearing their body of all that inedible material they will be feeling a lot better.

Is Your Cat Anxious?

If you are seeing your cat constantly eating grass this could be a sign of anxiety or displacement behaviour. In the same way you may see a cat over-grooming, chewing on grass may be your cats way of dealing with stress or anxiety. If you are worried your cat is eating too much grass or is showing signs of stress then it is best to take them to a vet to get checked out.

Your cat may actually enjoy the taste or texture of grass, they may even use blades of grass as a target for hunting practice too. If your cat seems to enjoy grass then there is no harm in this, as long as the grass is non-toxic and being consumed in small amounts.

Not All Grass is Safe

While grass is generally safe for cats, the biggest issue is if your cat is consuming grass that has been treated with pesticides or herbicides as this could be very toxic and lead to your cat being poisoned. The other issue is that if your cat does not have access to safe grass, they may ingest other plants and greens that could be toxic to them. There are a number of plants that are naturally toxic to animals, Cats Protection shares important information on dangerous plants here. Eating toxic vegetation can be fatal, it is crucial to know the signs of poisoning so you can act quickly and get your cat the medical treatment needed.

Although the signs can vary greatly depending on what has been consumed and the severity of the situation, these are the most common signs of poisoning:

  • Vomiting
  • Diarrhoea
  • Difficulty breathing
  • Lethargy
  • Drooling
  • Excessive thirst
  • Loss of appetite
  • Blood in vomit, stools or saliva
  • Pale gums

What Should I Do if My Cat Eats Something Toxic?

If you see your cat eating something that is toxic, take your cat away from it immediately and call a vet. Knowing what your cat has ingested will help the vet treat your cat appropriately. It is important to get your cat to the vet as quickly as possible as this will increase their chances of survival. Without treatment, the poisoning could prove fatal.

Can I Offer My Cats Grass?

If you would like to grow some grass specifically for your cat to graze on at their leisure, you can buy cat grass or cat grass seeds from many pet stores. Cat grass is basically different types of grass that is completely safe for cats to ingest, it is a great way of guaranteeing you are planting or offering suitable, non-toxic vegetation. It is easy to grow and can be grown in pots too so you could grow it for indoor cats too.

I recommend growing a patch of cat grass in your garden or in a pot in your house so your cat has the option of eating it if they feel they need to. This also prevents your cat from searching for grass elsewhere and accidentally ingesting something toxic. It is best not to offer grass to kittens as it can be too harsh on their digestive system, particularly if your cat is younger than 4 months old.

Is Eating Grass Harmful to Cats?

The only real concern with cats eating grass is if it becomes an obsession and they eat too much of it or if they eat toxic plants or grass that has been treated with some kind of chemical. With that said, eating grass is typically not harmful for cats.

Can Cats Eat Other Plants?

There are countless plants that are toxic to cats, this is something to be aware of if you have houseplants around your home. It’s best to make sure any plants you do have are nontoxic or are in areas of the home your cat cannot get to. While some plants are not toxic they could still cause mild gastrointestinal upset and those that are toxic could be life-threatening.

Some of the most common plants that are toxic to cats include; aloe, American yew, apple, arum, lilies, begonias, bird of paradise, bishop’s weed, branching ivy, cardinal flowers, chives, corn plant, daffodils, foxglove, ragwort and sweet pea. This is just a few of many, the ASPCA provides a toxic and non-toxic plant list here.