Josey Pro Kold
Your horse's body sounds its "call to arms" whenever he experiences an injury. In many instances, his temporary physical ailments will fall into the general category of soft tisseu trauma. This classification includes open wounds, closed wounds (where the damage is contained beneath unbroken skin), strains (where tissue fibers are stretched), sprains (where tissue fibers are torn), and bruises. But no matter what the injury's particular type, your horse's body will react in only one manner: by initiating the first stage of healing, known as the inflammatory response.
Immediately after injury occurs, the blood vessels that have been damaged begin to hemorrhage internally and / or externally. (In all but the most traumatic and extensive wounds, the natural mechanisms that control clotting will kick in within the first three to five minutes following injury.) At the same time, the cells that have suffered injury release enzymes and proteins which signal the body that its defenses have been breached. The enzymes transmit their message in several ways: 1) by activating local pain receptors; 2) by increasing the permeability of the blood vessel walls; 3) and by attracting immune chemicals and immune cells - the body's "clean-up crew" - to the site via a rush of fluids which begin to accumulate and cause the area to swell (edema formation).
Yet as beneficial as all of these actions are intended to be, they wreak havoc as well. The excess fluid - which may flood the site over a period of a few minutes or many hours depending on the injury's extent - creates a swamplike environment that separates healthy cells in the vicinity from their life-giving oxygen source. As a result, though they may have escaped injury internally, many are unable to survive without sufficient oxygen. This secondary tissue trauma is called hypoxic (literally, insufficient oxygen) injury, and paradoxically, it can give rise to even more extensive cell destruction and edema formation than the original trauma suffered by the horse. As a matter of fact, the point at which there is maximum infiltration of the body's healing forces in response to the original injury is also the point of maximum secondary cell destruction.
The goal, then, of any therapy for soft-tissue injury is to break the cycle of primary injury / secondary injury / excessive fluid accumulation / cell damage by subduing the unintentional self-destructiveness of the healing response. Though even properly applied cryotherapy has no significant effect on tissue damage during primary injury, it can dramatically decrease the amount of tissue lost to secondary injury. It accomplishes this by reducing the metabolic activity of the still-healthy cells.
