The sodium from most broth would worry me. Dogs can't tolerate much salt. Wouldn't use bullion cubes; I'd boil some bones to make the broth. (Actually just take some venison stock out of the freezer.) Not that a few would hurt, more likely my dogs getting into an entire batch.
My dog club does a few shows a year. We sell homemade dog biscuits as a fundraiser at some outrageous price (three for two bucks or something like that). Most of the folks feed them to our dogs in the booth. They sell better than girl scout cookies.