animal (horse) speculum & tooth float

On the right of the photo is a blacksmith forged horse speculum. It is used to keep the horse's mouth open when filing down a horses teeth (a horse continually grows it's teeth through out it's life).
If a condition occurs that the teeth wear unevenly, the animal has difficulty chewing it's grain. This results in the grain falls from the animal's mouth and prevents it from the nutrients that it needs to perform chores properly. The tooth float, (located on the left of the photo) is the tool by which the vet or the homesteader, as it may be, can remove this uneven wear in the teeth. The float has a rasp or file clamped into the float that does the work of filing down. Unlike the sensitivity in a human's teeth, the horse feels no discomfort in having this done. I have seen a vet use a bolt cutter to nip off an uneven tooth of a horse, and it shown no sign of discomfort or pain during this process.