Cats are obligate carnivores: they are dependent on meat to fulfil their dietary needs. So why on earth does your pet cat seem to enjoy munching on grass so much? This common pet cat behaviour has baffled cat owners for years, and there is still some ongoing debate as to the true reason. There are various plausible theories that’ll we will discuss below. And we’ll leave it up to you as to which you think is the most likely – or maybe all of them are true?

Reasons why cats eat grass

Here are the most common theories for why you may find your feline friend munching down on some of the green stuff. 

1) A digestive aid

Cats in the wild naturally consume prey – such as voles, mice, birds – and they tend to eat the whole thing. Some of these body parts are less digestible than others, such as bones, feathers, and beaks. Eating grass can induce vomiting in cats, which could be your cat responding to an instinctive need to bring up those non-digestible parts of their prey. Deeply ingrained behaviours such as this can well continue even if your cat has been happily munching highly digestible cat food for years. 

Eating grass can also help tricky things that your cat has eaten pass through the digestive tract. The grass acts a bit like a laxative, helping large and non-digestible blockages such as hairballs pass safely through. Grass is very fibrous; the long strands can help wrap around these tricky bundles of material and pull them through the gastrointestinal tract. 

2) Nutrition

Although cats are carnivores, there are certain nutrients they may look elsewhere for. Grass is thought to contain folic acid. This is essential in the production of haemoglobin, which is needed by the blood to carry oxygen around the body. Folic acid also supports growth and development. Grass also contains trace amounts of vitamins A and D. It has been theorised that cats in the wild would eat some plant matter via the stomachs of their herbivorous prey, and now have to supplement this for themselves. Your cat seeking out some grass to snack on may well be making a healthy choice. 

3) Pleasure

It may well be that your cat just likes grass! The taste and texture of grass is unlike either commercial cat diets or their natural prey. So it may just be that cats enjoy a little bit of something different. The action of chewing itself is also linked to the release of serotonin; a brain chemical that is linked with wellbeing. Your cat might just enjoy a chew of grass for the taste, texture, or pleasure of chewing. 

Is eating grass safe?

It is generally absolutely fine for your kitty to munch away on grass every now and again. But there are a few points to keep in mind. 

1) Amount and frequency

If you cat occasionally is to be found eating a small amount of grass, this is fine. If your cat sometimes vomits or regurgitates after eating grass, this is also not a worry. However, if your cat is regularly eating large amounts of grass, eating grass very frequently or vomiting frequently (more than once a week), this would be more of a concern. If you think your cat eats grass too often, is sick a lot, or their grass-munching habits have changed suddenly (such as suddenly eating grass a lot more often than before), book an appointment with your veterinary surgeon for a check-up. Mucus or blood in the vomit is also a concern and should warrant a vet trip. 

2) Treated grass

Grass is safe for cats to eat, but only if it hasn’t been treated with pesticides, herbicides or other chemicals such as fertilisers. If you regularly use chemical management on your grass, this may be a health issue for your cat. Cats will usually instinctively avoid chemically treated grass, but it is always better to be safe than sorry, and avoid harmful additives to areas that your cat can access. 

3) Toxic plants

If your cat is a determined chewer of greenery, ensure there are no plants in your home which may be toxic if eaten. Indoor cats may be especially predisposed to eating something unsuitable if they are motivated to eat grass but do not have outdoor access and therefore turn to the house-plants to fulfil their needs. There is a good guide to plants that are poisonous to cats here

Providing your cat with a safe source of grass is a good idea, as some cats are pretty determined to munch on the green stuff and the alternatives that they choose may not be safe. If your cat is indoor, or your outside space is not suitable, consider providing something safe for them. You can find commercial ‘cat grass’ which is safe for ingestion, or alternatives such as catnip, alfalfa, cocksfoot, barley or rye are all safe for cats to eat. 

In Conclusion

The sight of a cat happily eating grass may be a puzzling sight for many cat owners, but it is a common behaviour for our feline companions. The underlying reason is debated, but eating grass may well be a natural digestive aid, or a dietary supplement. Some cats just eat grass for the sheer pleasure of it! Eating grass is perfectly normal and safe for your kitty, as long as it is not in excess, and a safe source of grass is provided for them.

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