I guess I should clarify what I mean by human-grade
...those treats, and those companies that define the ingredient described as human grade, to be suitable for human consumption, i.e. Dr. Harvey's Whisker Smackers are not only made from poultry, beef or fish that could be sold in your local supermarket, they are processed in a facility that only processes human-grade items, using the appropriate standards for "for human consumption" meats (per a discussion I had with Dr. Harvey).
I agree that phrases such as "all natural" and "human grade", and even organic (one should check that it is actually so, that an item labeled organic is certified
organic), are to be taken with a grain of salt. But if one reads all that a company has to say about their ingredients, how they process the items being described, I honestly think you can come to a fairly safe conclusion.