Heat regulation is especially important for robust horses with thick skin and coat. Under certain circumstances, it is even the limiting factor when it comes to special endurance performances. Muscle work generates heat as a by-product, which warms the body and is dissipated again. In order to avoid overheating and thus circulatory problems up to collapse, the organism has various thermoregulation mechanisms at its disposal.
Autorin: Veronika Conen, CEO Sportsfreund Studios
As a reaction to the heating of its body, the horse begins to sweat. When the water in the sweat evaporates, the evaporative cooling occurs, which in turn serves to cool the organism. About 60 % of the cooling capacity takes place in this way. The effectiveness of this mechanism depends mainly on the prevailing weather. It works best in hot but also cold, dry weather, and worst in humid weather. Here, the air is already saturated with moisture and can no longer absorb additional water. So it can happen that a horse is less heated in hot but dry weather than in cool but humid weather. Sweating is healthy and can be a sign of good fitness. With progressing training more sweat glands are developed for higher capacities in thermoregulation.
When exhaling, not only carbon dioxide is expelled but also heat. The heated breathing air is exhaled and exchanged by cool fresh air when inhaling, which in turn cools the body. This mechanism provides about 33% of the cooling power. A need for cooling is indicated by accelerated breathing. This high frequency of breathing is known to Icelandic horse riders and dog owners as panting (the vast majority of horse breeds do not know this!). Panting is not to be confused with being out of breath. It serves to support the cooling system, especially when it needs extra capacity due to skin and coat thickness.
c) Heat Radiation
Radiation is the emission of body heat via the surface. The difference to the outside temperature plays a role here. Low temperatures and a brisk "breeze" are helpful. Dense fur, thick skin and a layer of fat hinder the release. For this reason, shearing helps especially on the chest and neck.
d) Heat Conduction
In this system of heat regulation, the contact of the warm body surface with cold matter provides cooling. The most common methods are ice bandages and washing down with cold water. Signs of overheating are exhaustion, a consistently high pulse and a temperature above 40 degrees.
e) Heat Convection
Heated blood is led via the veins into the capillaries on the surface, cooled there and returned to the inside. This form of cooling also works particularly well in breeds with thin skin. One is familiar with the images of thoroughbreds in sport, for example, whose skin is visibly criss-crossed with blood vessels. Icelanders, on the other hand, do not have this sight, which is why this form of cooling is available to them to a lesser extent.
You can improve the capacity of thermoregulation with training:
Degradation of fat as an insulating layer.
Expansion of the cardiovascular system, thus more effective removal of heat via the blood vessels. Expansion of the aerobic system, energy production through fat burning produces less heat, building of muscles, more efficient use of energy and less waste heat.
Riding at a steady pace promotes deep, regular inhalation and exhalation and thus heat exchange Endurance training promotes the formation of additional sweat glands for evaporative cooling.
As a rider, you can help your horse to cool down by leading it, because all the processes of heat removal work better when the horse is in motion. At rest, the after-sweating occurs: the heat removal from the inside slows down and the horse feels hotter again. The whole thing is compensated for by increased sweating.
An extremely effective support is cooling by hosing down or pouring cold water on the horse. It is important to always remove the water heated in contact with the horse.
An endurance performance is thus closely linked to the possibilities of heat regulation. Icelandic horses can easily cover the same distances as Arabian horses in endurance sport, but at a much slower pace. This is not because they cannot run as fast, but because they cannot cool down as quickly.