26/04/2016
The three main symptoms of inflammation--pain, heat, and swelling--occur in varying degrees, depending on the site, nature, and severity of the problem. All three symptoms are natural and functional responses to an injury. Pain alerts the horse to the problem and warns him not to use the affected area. Heat is an indication of the increased blood flow to the injury site, and swelling (or edema) helps immobilize the area.
When inflammation rages out of control, however, it actually can hinder the healing. Excess edema can create a "swamplike" environment, which makes it difficult for healthy cells in the vicinity of the injury to get enough oxygen from the blood (in essence, the cells drown). The result is secondary tissue damage called hypoxic injury, which can compound the problem. In addition, blood vessels in the area are put under increasing pressure by the fluid build-up, so the flow of blood and lymph tends to stall. Often, edema can interfere with an accurate diagnosis of the underlying injury--so your first goal is to reduce the swelling and discomfort.
The safest way to break the destructive cycle of secondary cell injury and excess edema is to use the horse's natural mechanism--his circulatory system--to sweep away excess fluids that have collected in the tissues. (While anti-inflammatory agents like bute can reduce swelling and heat, they also can mask pain and confuse the diagnostic picture.) There are two ways of encouraging this--applying heat, and applying cold. Heat should never be applied to an acute injury.