Grinder for lamb ribs

Have any of you ground up lamb ribs with meat in a grinder?  I have the LEM grinder which easily grinds whole chickens (I cut them into pieces that will fit in the grinder).  So it even grinds the drumsticks, but up to now I have been hesitant to put rib bones in there as it was sort of expensive and I don't want to break it.  I let my border terrier chew 1/3 of a rib rack while I supervise, and his teeth do great on the bones, but he is older and sometimes I don't have time to supervise, so I would like to get the bone into his lamb meals as well....any thoughts?