My cat eats too much grass – Is that normal?

My cat has been eating a lot of grass lately, to the point of getting my attention and concern. I wanted to know if this behavior is normal and if eating too much grass could be bad for her. Through my investigation I learned that this topic is controversial and that there’s no agreement about the causes of this. But as cat owners, there are things we can do to help if we have a cat that is obsessed with eating grass.

Why do cats eat grass?

Investigators have not come to a conclusion why cats display this curious behavior. However, there are some theories that could answer the question of why cats eat grass. Some of these theories are:

1. Get rid of hairballs. Grass can’t be digested by cats so they make themselves vomit in order to get rid of it.
2. Vitamin deficiency. If a cat has GI disease, grass may help to replace the deficiency of vitamins.
3.  Get rid of worms trough defecation.

There is no scientific data that supports any of these theories and some investigators think that cats show this behavior as an inherited survival instinct.

Is eating grass a behavioral instinct in cats?

According to Benjamin L. Hart, Professor of Physiology and Cell Biology School of Veterinary Medicine University of California, eating grass may be a genetic predisposition inherited from the cat’s wild Felidae ancestors. He explains that more studies are needed regarding this, but eating plants seems to serve a biological purpose for cats. Another explanation is that the domestic cat’s ancestor— the wild Felidae specie— ate plants to get rid of intestinal parasites (zoonotic nematodes) since they were always exposed to them. This genetic trait has been transmitted to modern cats which is why they display this behavior.

Video of my cat Sophie eating home grown cat grass

Is grass bad for cats?

Unless your cat is eating grass with toxic chemicals, eating grass is not bad for cats, actually quite the opposite. According to Liz Eastwood, author of “6 Natural Ways to Help Your Cat Live Longer”, 60% of the cats that outlive the average of 13 years frequently ate grasses. This means any type of grass, either indoor grown cat grass or grass naturally grown. The reason behind this is that grass provide chlorophyll and B17 that have anti-cancer properties. Grass also contains Vitamin B7 (Biotin) that helps convert proteins, carbohydrates and fats into energy, and Vitamin B9 (Folic Acid) that aims blood oxygen levels, synthesis of DNA, metabolism and proper growth and development in cats.

How much grass is too much?

If your cat is obsessed with eating grass and it shows lack of appetite and lethargy you may want to get your cat checked at the Vet to discard possible GI issues or some vitamin deficiency. If your cat is active and alert, has a healthy weight, has normal bowel movements, eats normally and just loves eating grass, you shouldn’t worry about it. Just make sure to provide your kitty with healthy cat grass for him to chew on.

If your cat is beyond a grass lover but obsessed with grass, most likely he also eats other non-food items at home. This is called feline PICA and it’s a tendency of some cats to eat things such as cat litter, plastics, paper, shreds, etc. Some breeds are more prone to show this behavior than others, such as Siamese, Birman or Burmese. The cause of PICA in cats can be biological or psychological. Cats that have diabetes, hyperthyroidism, or have an immunodeficiency virus may display this behavior. Also, stress, anxiety or boredom could also trigger PICA in cats.

If your cat eats non-food items at home constantly and eats a lot of grass to the point of you being concerned (like more than 10 times per day), take it to the Vet to discard a medical condition. If a health issue is discarded it means  this PICA condition is due to psychological problems. To help with this, increase your cat’s activity by playing with your kitty more. Also, keep a healthy routine for your feline friend in order to eliminate possible feline depression, stress, anxiety or boredom. Don’t leave him alone too long or manage ways to entertain your cat while you are away. If your cat reduces its habit of eating non-food items, just let him eat grass since it’s a healthier way to redirect the chewing behavior towards sometimes harmless.

What’s the best type of grass?

There is a variety of grasses that are healthy for cats: wheat, oat, barley or rye grasses. A type of grass that cats really like is called Cocksfoot; this grass has long leaves making it easier for cat to nibble. You can grow Cocksfoot at home to keep a good supply of this grass for your kitty.

My conclusion

It is not harmful for cats eating grass grown at home, and actually, the chlorophyll and B vitamins present in grass could be beneficial for cats, making them live longer. Eating grass is a common behavior in cats and there is not enough scientific evidence to support conclusively the reason for this. Eating grass may be a genetic trait that domestic cats carry from their wild ancestors which, on the end, benefit the kitties by improving their gut health.

If your cat eats food normally, has regular bowel movements, healthy weight, it’s active and he eats too much grass I suggest you not to worry about it and simply provide your kitty with fresh cat grass grown at home. Test different varieties until your cat chooses its favorite. If your cat is obsessed with grass and shows signs of feline PICA, take your kitty to the Vet to discard possible medical issues.

In my case my cat Sophie lives with a virus that she keeps at bay, in neutral mode. Though she is a healthy, active and happy cat, she does display PICA behavior. Sometimes, she eats non-food items at home and she is obsessed with eating grass, so feline PICA—maybe due to the virus in her body— could be the cause of it (I keep her checked with the Vet regularly). Since Veterinarians think that grass could help cats with their immune system by improving their gut’s health, providing some important vitamins and chlorophyll, I decided that I will keep giving my cat home-grown healthy grass for her to nibble on because it won’t hurt her and instead, will improve her health.