Trench foot
Trench foot can be prevented by keeping the feet clean, warm, and dry. It was also discovered in World War I that a key preventive measure was regular foot inspections; soldiers would be paired and each made responsible for the feet of the other, and they would generally apply whale oil to prevent trench foot. If left to their own devices, soldiers might neglect to take off their own boots and socks to dry their feet each day, but if it were the responsibility of another, this became less likely. Later on in the war, instances of trench foot began to decrease, probably as a result of the introduction of the aforementioned measures; of wooden duckboards to cover the muddy, wet, cold ground of the trenches; and of the increased practice of troop rotation, which kept soldiers from prolonged time at the front.
Horse grooming
The most basic form of hoofcare is cleaning, or "picking out the feet". A hoof pick is used to remove mud, manure, and rocks from the sole of the hoof. Removal of mud and manure helps to prevent thrush, a common hoof ailment which in very severe cases may cause lameness, and the removal of rocks helps to prevent stone bruises. In the winter, hoof picking also provides the chance to remove packs of snow from the horse's hooves, which can cause uncomfortable "snowballs". Additionally, when the hoof is cleaned, it can be visually inspected for problems such as puncture wounds due to a nail (which has the potential to be very serious if left untreated).
All crevices of the hoof are cleaned, particularly the sulci between the frog and the bars, as those areas are most likely to trap rocks or other debris, and also are the most common area to develop thrush. It is best to work the hoof pick from heel to toe, so to avoid accidentally jabbing the horse's leg, the frog of the hoof, or the person using the pick. When picking the feet, the groom stands at the horse's side, facing the tail of the horse, then slides his or her hand down the horse's leg. If the horse was not trained to pick up its foot when a person runs their hand to the fetlock and lifts lightly, most horses will pick up their feet if the tendons behind their cannon bone are squeezed. Some horses, particularly draft breeds, may be trained to pick up their feet to pressure on their fetlock.