I try to give my dog a dog biscuit every couple of days, they're a hard biscuit-based dietary supplement, similar to human snack food.
I give mine a dog biscuit every day when he goes to sleep.  Do you think they are healthy?
I'm kind of torn, I think probably they aren't, but the hard and dry texture probably helps clean their teeth, at least according to some manufacturers.
I want to believe that, anyway I don't think one every day can cause much daamage, specially for a big dog like mine.  
Yeah that's probably true, it's crazy to think that dog biscuits have been around since the Roman times, where they were called "Dog's bread."