Do Cats Eat Grass When They Have Worms?

Do Cats Eat Grass When They Have Worms?

Cats are smart, inquisitive animals that love to explore, especially in the great outdoors. While outdoors, you might have noticed your cat eating grass, and if so, you may have wondered what would prompt such odd behaviour. It might surprise you to know that, just like humans, cats have natural ways of healing themselves from certain ailments. They tend to chew and eat grass when they detect something wrong in their system. 

Do cats eat grass when they have worms?

Yes, cats will most likely eat grass when they have worms. Since grass is rough and indigestible to cats, it could help flush any parasites out of their guts as it passes through. Regular grass is safe for cats to ingest as long as there are no pesticides or weed killers on it. If your garden grass is treated, however, you should take precautions to keep your cat away or use mild fertilizers and pesticides. 

If you want to discourage your cat from eating grass, buy some cat grass. This is a type of potted plant that has safe grasses which cats can chew on. Other safe alternatives are catnip and mint. 

Why do cats eat grass?

Cats tend to eat some greens in their diet, such as grass, due to the prey that they eat. They may also eat grass to help them vomit, to ease an upset stomach. However, their digestive systems are not used to eating grass as this is not their regular food. 

Eating grass can stimulate a cat’s gut to pass things either way. This is useful when cats have bones or feathers in their stomach. The stomach acid is not strong enough to break down bones and feathers, and these can get stuck. In this case, cats will induce vomiting by eating grass.

Similarly, hairballs could form during a cat’s normal grooming, because cats pick up hairs with their tongues as they lick their fur. Some of the hairs get swallowed and if these are not passed through the stool they could form into large, matted balls. Cats expel these by coughing or vomiting. Most owners view the grass-eating habits of cats as a means of stimulating the vomiting reflex.

Cats are also believed to eat grass to expel worms or intestinal parasites by stimulating vomiting or diarrhea. The grass that is not properly digested in a cat’s stomach can entangle the worms and force them out of the gut.  It is believed that kittens eat more plants than adult cats because they are more prone to parasites. Kittens are smaller and worms tend to have a comparatively large effect on them. 

Grass also acts as a natural laxative. It can stimulate your cat’s digestive system, which meat cannot do. Grass contains fiber that encourages a cat’s gut to work harder and helps your cat to form a healthy stool. Fiber stimulates the gut to move quickly, which is an advantage if your cat is feeling constipated. 

Grass also contains folic acid and a surprising number of nutrients such as vitamins and minerals that are essential to cats. Folic acid is also found in a mother cat’s milk. It aids digestion, supports cell growth, and is beneficial for the production of hemoglobin which transports oxygen through the bloodstream.

Cat experts also believe that cats have the urge to eat grass if they are deficient in certain vitamins. This is often observed among cats that suffer long-term deficiencies due to incorrect diet or the presence of tapeworms. 

Is it safe for cats to eat grass?

Yes, it is generally safe for cats to eat grass, as long as it is normal wild grass. However, if your cat is eating garden grass, you should be wary. Garden grass could contain fertilizers, herbicides and pesticides to help it grow or to kill weeds. If cats eat the treated grass, they could get sick. To avoid this scenario, do not allow your cat outdoors if you treat garden grass with these chemicals. You may also opt for organic or mild pesticides and fertilizers. 


Cats tend to eat grass when they have worms since it stimulates their gut to pass things through vomiting or diarrhea. The plant matter which is not properly digested in the stomach can entangle worms and force them out of the gut.

Image: / -ElzbietaSzulmajer