I've Tried Everything! ... My Dogs Hate Dog Biscuits .....?
Different dogs, different tastes. Over time, my two have become very particular about what they will eat. For years, my older dog stuck her nose up at Milk Bone, now she likes them. I just gave them a Bil-Jac biscuit last night, and while the old one ate it, the younger greyhound didn't. I've purchased them in large sizes and like to switch off day-to-day, but I think the older larger packages go stale over time I try all kinds: high-end from the indy pet store, generic and big brands from the grocery/discount stores, and dollar packages from Dollar Tree. So from my experience, here are some thoughts:
* offer them variety
* beware when the biscuits might be a little stale - the dogs will let you know
* my guess is the dogs you meet on your route are less discriminating than your friends at home
* There's one I find they like pretty consistently that isn't too expensive: Breath Busters from Pedigree. You can sometimes find a sale or coupons.
* hard biscuits are better for their teeth than soft ones
* make your own - many good recipes out there. It will stink up the house, but I don't know of any dog that can resist a treat made mostly of pureed liver. Many recipes and some books out there.
I give them a very good quality dog food, so I don't worry so much about the ingredients of the occasional dog biscuit, although the home-made kind are great.