Believe it or not

If you are like me, you get lots of emails warning you about the danger of this or that common household substance, and it is hard not to wonder whether you should immediately eliminate all plastic water bottles and such things, which in any case are only something we need because some marketer somewhere has convinced us we need them.
Yesterday I got an email about clumping cat litter, which is a popular commodity around my house. Even though Shadow doesn't poop in the litter box but rather on the floor, no matter how spotless the box is (and that is one thing I am very careful to clean frequently), she does urinate in the box, and Whistler does all his business in the two boxes we have in the house.
This email told of the deadly threat presented by this kind of clumping litter, which, according to the several people who wrote in about their cats' negative experiences with the stuff, can be swallowed and expand inside the intestine to cause dangerous obstructions. Even if cats don't get obstructions, some writers claim that this substance has carcinogens in it, and has caused cancer in some cats.
I think that I will try to change litter when I finish the clumping litter I have, but I have tried several kinds of litter with these cats, and this is the kind they seem to like best. I can't have them urinating outside the boxes and I don't want to see Whistler pick up Shadow's bad habit of pooping on the floor or carpet.
I called the vet and she said that she has seen no cats who have experienced problems with this stuff. Dogs, however, are a different story. They tend to eat this litter, and it is not good for them. Cats apparently have more sense, or don't like the flavor and so quit after a few pieces.
It's hard to know what to believe anymore.