I can't say I have any experience of eating a donar kebab in the last few years. My instincts tell me that if you just eat the meat and salad without the pocket you should be pretty safe.

However, the kebabs are offcuts of meat all compressed together, a bit like mince, and so it is possible that some filler is used as well to bind it together better. Whilst they may be good for the ocassional foray I think they could be a bit like beefburgers, unpredictable, unless you know how they were put together.