Pepperoni has soooo much grease in it, it can't be good for them. But I don't thnk a snagged piece every once in a while will hurt. My Lil Bit has a pepperoni fetish....and has a fit whenever we have pizza. One little bite is all she gets...and it makes her happy.
Here is something useful to know: Holly Golightly, the feral cat I rescued from KFC, survived a whole year by eating fried chicken! The employees told me that she had been hanging out at their parking lot for nearly 12 months. They fed her chicken wing each night. Plus, she ate trash from the lot. When I found her, she was perfectly healthy except for asthma issues. So, I wouldn't worry about the preservatives and grease in one pepperoni,
Well... got a big puddle of kitty throw-up on the floor last night. So I guess something didn't agree with somebody's stomach. Three guesses what, and the first two don't count. Serves ya right, kitty (and serves me right for not watching my pepperoni better)!