I have three, strictly house cats. If you allow your cats to go outside, which I know they love, they are prone to all kinds of catastrophies. Mainly getting run over, a neighbor's cat was recently killed by a car, and we live on a quiet street. Mine have never been outside so they don't know what they are missing.
I had a beautiful, sweet, Maine coon cat, Poo Bear, in my earlier days. He was allowed outside of an evening. He was big and fat and suddenly he became very thin and ill. He was diagnosed with feline aids. I didn't know there was such a disease. A few years later I was talking to an old neighbor who had lived near us when I had Poo Bear, and she said her cat Tommy had died of feline aids. Tommy used to come over in our yard a lot, so I am sure that is where Poo Bear got it. I remember Tommy got to looking very ill, long before my Poo Bear got sick. My other cats didn't get it, because you have to have a scratch or a bite to get it in your system. And Poo Bear always liked to scrap a little, so Tommy must have scratched or bitten him. No more outside cats.
I bring in grass too for the hair balls. They really like the grass that is rough and course like, I believe they call it saw grass.
It only grows here and there in clumps in our yard. I have a terrible time with the hair ball medicine, it is even tuna flavored now. Every one of them puts up a fight and runs away.
There must be a better way.
Mary Jo