<human>: Just got a new kitty, after my last one died of cancer 6 years ago. It took me that long to get over the loss, but now I feel I need some updates on brands of food and litter. 

I keep second guessing myself on what happened to my cat, he had liver cancer at age eight and the doctor told me that was not very common. So I wonder: Did he eat grass with pesticides? Was it  the food (I always got him the best recommended by the vet), the litter? 
I am sure pet products are not regulated as much as humans, so it crossed my mind that it could be anything really. What is the best brand for food these days? And litter?

Can you give me the gist of the text in a nutshell?
<bot>: Want to assure kitty safety, need recommendation for food and litter brands.His name is Big Bang, by the way.