Knowing how to effectively cool down your horse after strenuous exercise is a vital skill that every horse owner should develop, especially eventing riders. It is not only extremely important for the health and welfare of your horse, but is essential to successful recovery post cross country.
The most effective method of cooling the equine athlete after exercise involves the application of large volumes of cold water over the horses entire body, allowing the water to stay on the horses body for a brief period of time to absorb some of the horses body heat, removing the water with a scraper, and then repeating the process until the horse has cooled down. I like to refer to this as “Water On - Water Off, Water On - Water Off”.
The theory of Cooling
Despite the many evolutionary adaptions that the horse possesses that allow it to be the supreme athlete that it is, its efficiency of energy use during exercise if far from 100%. In fact, only about 30% of potential energy to fuel muscle contraction during exercise is effectively used and utilised, with the rest being lost as heat. This coupled with the large muscle mass of an equine athlete results in an enormous amount of heat that needs to be rapidly removed in order to reduce the serious side-effects of overheating.
Body heat can be lost via four principle ways: Evaporation, Radiation, Convection and Conduction.
Evaporation occurs when a liquid changes state into a vapour i.e. it evaporates. This change of state results in a cooling effect on the surface from which the evaporation occurred. It is the principle of evaporation that allows sweat to produce its cooling effect on a horse’s body. Equine sweat has two special adaptions to try and increase its effectiveness for cooling; the first is the production of a special protein called latherin. Latherin is the reason why equine sweat has its white appearance and it’s mode of action is to increase the surface area over which the sweat spreads. More surface area leads towards more cooling. Equine sweat is also slightly hypertonic. Hypertonic essentially means that the fluid has more salts in it than other fluids. Having slightly hypertonic sweat results in more fluid being drawn to the surface of the skin, which then leads towards more evaporation and more cooling but despite these adaptions, evaporative cooling alone is not effective enough to properly cool down a horse. Unfortunately the evaporation of sweat is even less effective in humid climates (high humidity slows down evaporation as the air already has a large amount of water vapour in it) and when there is little wind (wind helps to promote evaporation). Some heat is lost via evaporation that occurs within the respiratory system, but it is still not enough to effectively cool down a horse after exercise in a timely and efficient manner.
Transfer of heat via radiation is best thought of in relation to the production of heat from a light bulb or from the sun. It does not require contact of substances in order to facilitate heat transfer and is often referred to as thermal radiation. In the context of heat loss from a body, radiation is an inefficient mode of heat loss that does not contribute much to cooling of the horse.
This now leads us to convection and conduction; the saviours of cooling your horse and the theory behind “Water On - Water Off, Water On - Water Off”. Convection is the transfer of thermal energy from hot to cold places, and conduction is the transfer of heat between substances that are in contact with each other. These two principles when applied to cooling the equine athlete are highly effective ways of heat removal, as long as they are applied correctly (and you thought you would never need high school physics again…)
How does “Water On – Water Off, Water On – Water Off” actually work?
By applying large amounts of cold water to the horse’s entire body some of the heat that has been produced by the muscles transfers to the water. The water then heats up and the skin below cools down. This in turn cools the vital structures underneath. But the key to successful cooling is that this now warm water needs to be removed from the horse’s skin with a scraper. Otherwise it just sits there acting as an insulator trapping the heat of the muscles.
Hence “Water On – Water off”. It’s important to remember that the water needs to be in contact with the skin for a period of time (a few seconds) for it to be able to absorb the heat. There is no point pouring on vast quantities of water and immediately scraping it off.
What is the best way to cool a horse after strenuous exercise such as Cross Country?
The first step is to be like the scouts and “be prepared”. You will need ideally a hose, or 5 or 6 large buckets of water, a couple of sponges, one or two scrapers and a few pairs of hands. But don’t worry, one person, one bucket and once sponge will be adequate – you just might have to work a bit harder. Plan ahead for the best place to cool your horse - try and find a place in the shade or somewhere to catch the breeze if possible.
As soon as the horse has finished get all tack off immediately. Boots, bandages, saddle cloths, saddles and hoods trap heat. Once they are off I like to start cooling by applying large amounts of cold water over the entire horse in a systematic way from nose to tail - “Water On”. The larger muscle groups of the hindlimb produce the largest amount of heat proportionally, as such they require the most amount of water, but don’t neglect the rest of the body and ensure to get up between the back legs and under the tail. This can be done with a hose or by bucket and sponge or a combination of both. Wetting the legs also provides an excellent opportunity to check for injury.
Now comes the time for “Water Off”. Try to get as much of the now warm surface water off as possible, ideally with a scraper, but if you don’t have one, or there are more helpers than scrapers, just using your hands will be fine. Don’t forget to remove the water that is collecting underneath your horse’s belly. Gravity leads to accumulation of water in this area and it is probably the easiest place to notice the difference in water temperature between water going on and water about to come off (thanks to our friends convection and conduction).
And then simply repeat, over and over and over again. Starting at the nose and working your way to the tail. “Water On – Water Off, Water On – Water Off”. If it’s possible it can be helpful to gently walk the horse a bit between cycles. This can help with cooling as it will increase evaporative cooling by increasing airflow and can also help muscle recovery. If you have enough helpers, walking and cooling simultaneously can also be very helpful.
A nice example of the systematic approach of starting at the nose and working towards the tail. Water is being applied by the hose and then scraped off several seconds later
One of the New Zealand high performance squad horses after successfully completing Blair Castle in Scotland. This is an excellent example showing that it is vital to cool down your horse properly after cross country, regardless of the ambient temperature. Cool or cold conditions will make recovery faster, they should not be seen as a substitute for effective cooling
A series of photos of a one star horse being cooled down after cross country using buckets and sponges showing a systematic approach from nose to tail as well as the walk and cool technique
When can I stop cooling?
If you are at a Three Day Event with a veterinary examination at the finish of cross country the FEI veterinarian will inform you when your horse has cooled down enough and is fine to go back to its stables. The veterinarian will make this assessment of the recovery of your horse’s heart rate, respiratory rate and temperature, along with a general assessment of the entire horse. An exam is usually performed as soon as possible after the end of cross country and repeat exams are done every 5 or 10mins until the horse is ready to leave the finish area. With effective cooling most horses are recovering well by 10 or 15mins. Temperature, respiratory rate and an assessment of your horse’s demeanour are easy to do yourself, and with a little bit of practice and a stethoscope, so too is heart rate.
The basic principle to understand is what is “normal” for your horse and to cool until your horse is showing signs of recovery, with a significant downward trend in heart rate, respiratory rate and temperature. It’s vital to remember that cooling your horse in an effective way should be done each and every time your horse does strenuous exercise, not just at the end of cross country. The amount and duration of cooling is proportional to the amount, duration and intensity of exercise, but still just as important when done at home as when done at an event. And if you are in doubt about when to stop, there isn’t really such a thing as too much cooling.
What is the best way to learn how exactly to cool my horse, especially post cross country?
Regardless whether you are a young event rider doing pony club or interschool event, or a seasoned campaigner who can’t remember a time that you didn’t own a horse, I truly believe that the best way to learn (or re-learn) how to effectively cool down a horse is to go and watch a professional rider cool down his or her horse at a three day event. The finish area of cross country at a big three day event is quite a sight to be seen, and you can learn an amazing amount from theses riders. Quite simply, if it’s what they do for their horses, it’s what you should do for your horse.
Who decided that this is the best way to cool a horse?
Unfortunately it took a very long time for anyone to actually do scientific research into the most effective way in cooling horses post strenuous exercise. It wasn’t long ago that throwing a wet towel over a horse’s rump or neck and marching it around in the sun for 10mins was deemed appropriate. Sadly it took a tragic chain of events at the 1992 Barcelona Olympics that resulted in the death of a horse from heat exhaustion to push the research. But thankfully due to the enormous efforts of a team of highly respected international veterinarians lead by Professor Leo Jeffcott of the University of Sydney Veterinary School in the build up to the 1996 Atlanta Olympics that a large body of research is now available. It shows with little doubt that this is the most effective way to cool horses post strenuous exercise.
What not to do…
Research in this field continues to this day, often spurred on by choice of Olympic cities with climatic conditions less than ideal for equestrian events (Sydney, Athens, Hong Kong, and now Rio de Janerio). It has led to many innovations and protocols regarding the welfare of horses competing in hot and humid climates. These include misting fans and misting tents to increase evaporative cooling and the use of the wet-bulb globe temperature (a composite temperature that estimates the combined effect of temperature, humidity, wind speed and radiant heat from the sun) to determine the most appropriate time of the day for equestrian competitions, or if a cross country course may need to be shortened to ensure the welfare of horses competing.
The misting tent at the 2008 Beijing Olympics in Hong Kong. Large fans with a sprinkler system attached blow mist over the horses to increase evaporative cooling. All water out of the hoses was chilled to 3˚C
In Summary
Cooling your horses is all about “Water On – Water Off, Water On – Water Off”.
Hopefully this article has helped you better understand how to effectively cool down your horse after strenuous exercise, but if you do still have any questions about cooling your horse – simply ask your veterinarian. Or come and find one of us at the end of cross country next time you are at a competition. We are here to help!
Good luck out there, stay safe, and please bring your horse and yourself home in one piece after cross country so we can help you cool him or her the best way possible.
After becoming a Diplomate of the American College of Veterinary Sports Medicine and Rehabilitation in February 2017, Christopher Elliott BVSc (Hons) MRCVS returned to the UK and works for Lambourn Equine Vets – an ambulatory veterinary clinic with a long and proud associating with the highest levels of British Eventing. He has vetted at many of the major eventing competitions around the world Find out more about Christopher here or follow him on Twitter @Chris_BVSc
