Yeah I would stay away from the smoked/cooked bones sold at pet stores.. I have always given Titan raw marrow bones. One time I ignorantly thought "how bad could they (cooked pet store bones) be, i mean they sell them a lot, can't be that bad." He shattered tha tbone.. I mean literally shattered, like glass. I thank God I was watching him because I was able to stop him and get all the pieces. SO needless to say I steer people away from them.
Like Shade said.. get Marrow or knuckle bones.. or even rib bones, we're going to try those, as I heard they are great too. They should sell them all at most grocery stores that have their own butcher.. they are not expensive either.
Many people use antlers too, and we just tried our first Ram horn and it was a hit for a couple weeks. still go back to the arw bones though.
Also, while rancid meat may affect the dog's stomach, good raw meat and bones wont. You should read a little on the B.A.R.F forum.. it's all about a raw diet for their dogs. Pretty interesting stuff.
Commander Charly Titan (GSD)-15 Jan 2010