I had to learn the hard way with that stuff. Harley is my first Ferret got him last Christmas so I am still learning the shoulds and shouldn'ts. My cats were doing fine with it and so was he but in the last week my new little girl, Yoshi got sick from that stuff. The box says non-toxic. So I thought it was fine. I never thought a ferret would eat it. She is fine now. Luckily, VERY luckily it all passed, but not without pain. I took her to the Vet a few times so she could check her out to make sure everything was moving fine. UGH. I Feel like such a horrible mommy! I'm very glad Yoshi is fine now. She is playing like her normal self and eating and drinking fine. :o) Again a hard lesson learned! I'm not even using it for my cats anymore just incase the cats track it around. ~Toni~ Harley & Yoshi [Posted in FML issue 3399]