Horses that are hot (above 40 degrees C or 104 degress F) and competing in hot environments (above 26 degrees C or 80 degress F) and are cooled quickly during or after competition are less likely to suffer heat stress, will recover more quickly, will not become as dehydrated and are almost certain to perform better. There is no evidence that this technique causes any muscle problems such as 'tying up'.
Any horse at any competition or show at any level in any country can suffer from heat stress - this includes event horses, dressage horses, show jumpers, racehorses, polo ponies, endurance horses, driving horses, and horses or ponies in gymkhanas.
The cold water cooling technique cools horses using two of the three ways they normally lose heat - convection and evaporation. You need the following equipment:
- Large buckets to hold 40-50 litre of water and large blocks of ice
- Supply of more water close by - hose or tanks
- Small buckets (5-10 litre) - supplement tubs are ideal!
- Assistants - 3 is ideal - one to hold the horse and one person to cool each side
- A shady spot to carry out the cooling
Start to cool the horse immediately it finishes exercising while taking the rectal temperature. Liberally apply cold water to all parts of the body including the quarters (this is where most of the large muscles used for movement are located and so is an area that gets particulalry hot)
Do not scrape off excess water after each application, it is more important to continue to apply cold water. Carry on cooling the horse, alternating 20-30 second cooling periods with 20-30 second walks in a circle. The walking and cooling sequence is important. The walking promotes blood flow to the skin and cooling by convection; the movement of air aids cooling by evaporation.
Check the horse's rectal temperature at intervals. The temperature should fall by around 1 degree C in 10 minutes. Allow your horse to drink small amounts of water (half a bucket) during competition (e.g. during the 10 minute box in 3-Day Eventing), between rounds (e.g. Showjumping) during long warm-up periods (e.g. Dressage) and immediately after exercise - it will help to cool the horse down and reduce the effects of dehydration.
Stop cooling if the rectal temperature is less than 38-39 degrees C, the skin over the quarters is cool to rouch after a walking period, if the respiratory rate is less than 30 breaths per minute and if the horse shivers continuously.
Don't forget that the rider can also suffer from heat stress. To cool the rider, remove their hat, sit them in the shade, wash their face with cold water (which makes you feel better but is not very effective at reducing body temperature) and encourage them to drink an isotonic drink such as Locozade Sport or Isostar (isotonic means the same concentration as body fluids). The rider should also wear light coloured (preferably white) loose fitting cotton clothing. In addition, the hat hould be lightweight and a comfortable fit.
Do not put ice in the horse's rectum as it can hide a high temperature - preventing the horse receiving appropriate cooling and other potentially life-saving trreatments.
Don't hold small bags of ice against the skin on the head, neck, quarters or anywhere else - this reduces cooling by stopping skin blood flow to the area under the pack. Instead, concentrate on cooling as much of the body surface as possible with cold water.
Do not place wet towels on the horse. Although at first the towel may be wet and cool, it soon warms and acts as insulation, preventing the loss of heat.
Excessive application of grease prior to cross country limits sweating. The grease acts as insulation, prevents sweating and limits sweat evaporation.
Do not let horses stand still for long periods.
Do not prevent the horse from drinking small amounts of water during competition. Water should be left in the stable until 15-20 minutes before exercise. Water is emptied very rapidly from the stomach.
Do not give the horse ice cold water to drink.
Do give some hard feed and hay up to 4 hours before exercise.
Muscles work more effectively when they are warm, so horses should be warmed up before exercise, and a moderate increase in body temperature will do no harm.
Remember that when the weather is hot the horse will warm up faster.
(Thanks and acknowledgement to the Animal Health Trust)
