We used to give our rotti apples and oranges quite a bit - as far as the seeds being cyanide - if any of you bite your nails, you're ingesting cyanide too. But I think that would be like poppy seeds showing up as heroin in urine drug tests - you probably have to eat a buttload to get that kind of result. Of course, every dog is different - so you might feed all your dogs apples and have one that has a serious reaction to it. And our GSD, Bunny, ate everything from citrus to chocolate (she loved m&m's). Also, you build up an immunity to things when you ingest them in small amounts over a long period of time - that's why you don't get cyanide poisoning from biting your nails!
I did find this site - I know that I had found another one that I think was better, but I didn't bookmark it and now I can't find it again