Is ti ok to give a 4-month-old kitty grass to eat?

Are you talking about regular grass? If so, I would not recommend giving your cat grass you plucked from the ground outside, regardless of your cat’s age. Who knows what pesticides and contaminants are on that!

However, there are grasses/fibers that are good for cats to aid their digestion. You can find cat grass seeds/growing kits at most any pet supply store. There are also a slew of online sites that you can use.

Here’s a website that discusses some of the benefits of providing your cat with home-grown cat grass: http://www.drsfostersmith.com/pic/article.cfm?aid=373

Note that it mentions that they should only be consuming small quantities. They mention that binge-eating of cat grass may be a result of a larger issue that warrants a vet visit.

Cats will sometimes bite on or nibble plants, either when they’re playing with it as a toy or sometimes the will intentionally eat it because they have a stomach ache.

There are some plants that are poisonous, look at this list here so you don’t accidentally give your cat any of these: http://www.cfainc.org/articles/plants.html

I agree with ziggy_bo43 that you should probably not let your cat eat lawn grass as there are often pesticides on it (even if you or your landowner or parents or whoever don’t spray the city or county might, they do in some areas, especially in the summertime), plus if it’s near a road there will be chemicals from the cars - oil, gasoline, etc - that can get in the grass.

My cat nibbles on grass to help her system. Don’t give it them, let it eat it itself when their outdoors.