I know that it is discussed in some of the other posts, but it needs a title of its own.
I've made my favorite cat very sick by using some of the "reputable name-brand" stuff from the pet stores. And I had another cat die that I had just adopted from the shelter after treating it with ear mite solution from the pet store. It was very sad, the cat was gorgeous, and I didn't have him long enough to get to know him. Never use anything from a pet store on anyone you love. It's all unreliable, and a high percentage of pets have allergies to those products, as the vet told me as she was trying to revive my poor suffering, dying, beautiful Pepe the cat (so named because he was black and white in the same places as a skunk, which I adore).
I never liked going in those pet stores, anyway. l'd have to practically run by all the cages where they kept all of those poor trapped animals, birds, especially. I was always depressed for hours afterwards.
And I wouldn't eat or use anything they sell at big box stores--not even the "organics"--they have low standards at the factory, or walmart wouldn't be able to afford stocking it.
I would avoid all products that contain essential oils, partly as they can be toxic (particularly to cats) but also, despite claims to the contrary, have been proven not to kill fleas (annoy them, perhaps, as cedar is annoying to pretty much all forms of life).