We don't, until we taste them. Most dog biscuts are actually edible. They don't have much flavor, except for the cheese kind; those are terrible, don't eat them. Of course, being people, we may not really have a viewpoint that would allow us the objectivity to decide that they would be tasty for dogs. So, in conclusion, we can't (munch munch) we can't really (crunch) have a definitive opinion until we (gulp) feed them to the dog and judge the reaction. Or, (rustle rustle crunch) try them ourselves (burp).