I give knuckle bones frozen, after a few hours I wrap them in plastic and put them in the fridge for the next day. After three days I throw them away. Sometimes I forget about them and the dogs show up with a nasty smelling bone after several days. No one has ever gotten sick from it, just diarrhea from the marrow. That's why I give this in the morning so it is out of their system by night.
Deja, GSD, sable WL, female, born 11 / 2013
Cam, Rough Collie, sable, male, born 8/2015