I believe they are hoof paring nippers. The Channellock catalog that I have shows two without the compound joint. One has one beveled cut that overlaps a square cutter. The other has replaceable jaws and it looks like the jaws overlap on it. The first one they call Improved Hoof Parer and the second one Out Pride Hoof Shear. The thing that most people at flea markets call hoof nippers, they call Heavy Duty Cutting Nippers designed for concrete form builders, carpenters, mechanics, famrets. etc. for easy cutting of large nails, small spikes, form wire ties, etc.
I think most farriers that I have met prefer the nippers (latter) to the parers (latter) because you can cut hooves and nails with the nippers. The parers are just for hooves. I have a much easier time selling the nippers and I find a lot more of them than the parers.