Cooling your horse
Professor Jo-Anne Murray
PhD, MSc, PgDip, BSc (Hons), BHSII, RNutr, PFHEA University of Glasgow Veterinary School
Temperature regulation in horses
Temperature regulation (also known as thermoregulation) is the ability of the horse’s body to maintain or return to its core internal temperature, which in horses is 38 °.
As horse owners, we should all be concerned about temperature regulation, especially when the weather is warmer and we are exercising our horses. In order for horses to survive, their internal body temperature is kept within a very narrow range (37.2 to 38.3 °C). Heat is continuously generated in the horse’s body as a result of metabolism and this increases during exercise when the metabolism of energy for exercise occurs and in thoroughbreds, for example, body temperature can rise by over 5 °C.
Horses are actually very efficient at losing heat and having an understanding of this can help us manage our horse’s temperature. Horses lose heat through various mechanisms: convection (heat is moved from deep within the horse into the air), conduction (heat moves from the horse’s blood to the air), direct radiation (heat radiates directly from the horse), and evaporation. Evaporation involves the removal of heat through sweat, the sweat that the horse produces evaporates and this cools the horse down. It is important to note that electrolytes are lost via sweating and these should be replaced in your horse’s diet. Restorelyte or Everyday electrolyte from Equine Products UK Ltd are ideal as this can be supplemented in powder, liquid or paste form and will replace lost salts and aid with recovery.
Although horses do not pant like some animals (for example, dogs) they do lose heat via respiration as well. The horse’s cardiovascular system also has an important role in temperature regulation by transferring heat from the site of production, such as the muscles, to areas of the horse where it can dissipate, such as the skin. For example, during exercise blood flow to the skin increases in order for evaporation of sweat to occur. When your horse is being exercised he will dissipate around 70 percent of the internal heat produced through sweating to ensure that his core temperature returns to its resting value. If this does not happen, then damage to internal organs can occur as a result of heat exhaustion.
The following is a list of signs that may indicate that your horses may be suffering from heat exhaustion:
- Decreased appetite
- Nostril flaring
- Dark urine
- Reduced performance
- Muscle spasms
- Irregular heart rhythm
- Slow recovery after exercise